diff --git a/src/wp-admin/includes/class-wp-comments-list-table.php b/src/wp-admin/includes/class-wp-comments-list-table.php
index 2b927a7f81a6a..d622ccf2111a3 100644
--- a/src/wp-admin/includes/class-wp-comments-list-table.php
+++ b/src/wp-admin/includes/class-wp-comments-list-table.php
@@ -103,12 +103,40 @@ public function prepare_items() {
 			$comment_status = 'all';
 		}
 
+		// The 'note' type is never listed here, so it is dropped from the request.
 		$comment_type = '';
 
 		if ( ! empty( $_REQUEST['comment_type'] ) && 'note' !== $_REQUEST['comment_type'] ) {
 			$comment_type = $_REQUEST['comment_type'];
 		}
 
+		/*
+		 * WP_Comment_Query drops the default exclusions when 'all' types are
+		 * requested, so they are also passed as 'type__not_in' to keep excluded
+		 * types out of the list table in that case.
+		 *
+		 * The requested type is removed from that list, so a plugin that adds
+		 * its own default-excluded type to the type dropdown via
+		 * 'admin_comment_types_dropdown' can still list it. Type aliases are
+		 * expanded first, matching how WP_Comment_Query resolves them.
+		 */
+		switch ( $comment_type ) {
+			case 'comment':
+			case 'comments':
+				$requested_types = array( '', 'comment' );
+				break;
+
+			case 'pings':
+				$requested_types = array( 'pingback', 'trackback' );
+				break;
+
+			default:
+				$requested_types = array( $comment_type );
+				break;
+		}
+
+		$excluded_types = array_values( array_diff( wp_get_default_excluded_comment_types(), $requested_types ) );
+
 		$search = $_REQUEST['s'] ?? '';
 
 		$post_type = ( isset( $_REQUEST['post_type'] ) ) ? sanitize_key( $_REQUEST['post_type'] ) : '';
@@ -155,7 +183,7 @@ public function prepare_items() {
 			'number'                    => $number,
 			'post_id'                   => $post_id,
 			'type'                      => $comment_type,
-			'type__not_in'              => array( 'note' ),
+			'type__not_in'              => $excluded_types,
 			'orderby'                   => $orderby,
 			'order'                     => $order,
 			'post_type'                 => $post_type,
diff --git a/src/wp-admin/includes/comment.php b/src/wp-admin/includes/comment.php
index f32bd91ad265d..2dac177afa90b 100644
--- a/src/wp-admin/includes/comment.php
+++ b/src/wp-admin/includes/comment.php
@@ -223,6 +223,8 @@ function get_comment_to_edit( $id ) {
  *
  * @since 2.3.0
  * @since 6.9.0 Exclude the 'note' comment type from the count.
+ * @since 7.1.0 The excluded comment types are derived from the
+ *              {@see 'default_excluded_comment_types'} filter.
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
@@ -242,7 +244,19 @@ function get_pending_comments_num( $post_id ) {
 	$post_id_array = array_map( 'intval', $post_id_array );
 	$post_id_in    = "'" . implode( "', '", $post_id_array ) . "'";
 
-	$pending = $wpdb->get_results( "SELECT comment_post_ID, COUNT(comment_ID) as num_comments FROM $wpdb->comments WHERE comment_post_ID IN ( $post_id_in ) AND comment_approved = '0' AND comment_type != 'note' GROUP BY comment_post_ID", ARRAY_A );
+	$excluded_types = wp_get_default_excluded_comment_types();
+
+	$type_not_in = '';
+	if ( $excluded_types ) {
+		$type_not_in = $wpdb->prepare(
+			sprintf( ' AND comment_type NOT IN ( %s )', implode( ', ', array_fill( 0, count( $excluded_types ), '%s' ) ) ),
+			$excluded_types
+		);
+	}
+
+	// $post_id_in is built from integers and $type_not_in is prepared above.
+	// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
+	$pending = $wpdb->get_results( "SELECT comment_post_ID, COUNT(comment_ID) as num_comments FROM $wpdb->comments WHERE comment_post_ID IN ( $post_id_in ) AND comment_approved = '0'$type_not_in GROUP BY comment_post_ID", ARRAY_A );
 
 	if ( $single ) {
 		if ( empty( $pending ) ) {
diff --git a/src/wp-includes/class-wp-comment-query.php b/src/wp-includes/class-wp-comment-query.php
index f80864d31c8bc..d99503e86ea78 100644
--- a/src/wp-includes/class-wp-comment-query.php
+++ b/src/wp-includes/class-wp-comment-query.php
@@ -544,6 +544,7 @@ public function get_comments() {
 	 *
 	 * @since 4.4.0
 	 * @since 6.9.0 Excludes the 'note' comment type, unless 'all' or the 'note' types are requested.
+	 * @since 7.1.0 The default-excluded comment types are filterable via {@see 'default_excluded_comment_types'}.
 	 *
 	 * @global wpdb $wpdb WordPress database abstraction object.
 	 *
@@ -779,13 +780,40 @@ protected function get_comment_ids() {
 			'NOT IN' => (array) $this->query_vars['type__not_in'],
 		);
 
-		// Exclude the 'note' comment type, unless 'all' types or the 'note' type explicitly are requested.
-		if (
-			! in_array( 'all', $raw_types['IN'], true ) &&
-			! in_array( 'note', $raw_types['IN'], true ) &&
-			! in_array( 'note', $raw_types['NOT IN'], true )
-		) {
-			$raw_types['NOT IN'][] = 'note';
+		$excluded_types = wp_get_default_excluded_comment_types( $this );
+
+		// Unless all types are requested, exclude each default-excluded type
+		// that the query does not explicitly request. The special type tokens
+		// in the request ('comment', 'comments', 'pings') are first expanded to
+		// the literal comment_type values they represent, so a type requested
+		// via an alias (for example 'pings' for 'pingback' and 'trackback') is
+		// still treated as explicitly requested and is not excluded.
+		if ( ! in_array( 'all', $raw_types['IN'], true ) ) {
+			$requested_types = array();
+			foreach ( $raw_types['IN'] as $requested_type ) {
+				switch ( $requested_type ) {
+					case 'comment':
+					case 'comments':
+						$requested_types[] = '';
+						$requested_types[] = 'comment';
+						break;
+
+					case 'pings':
+						$requested_types[] = 'pingback';
+						$requested_types[] = 'trackback';
+						break;
+
+					default:
+						$requested_types[] = $requested_type;
+						break;
+				}
+			}
+
+			foreach ( $excluded_types as $excluded_type ) {
+				if ( ! in_array( $excluded_type, $requested_types, true ) ) {
+					$raw_types['NOT IN'][] = $excluded_type;
+				}
+			}
 		}
 
 		$comment_types = array();
diff --git a/src/wp-includes/comment.php b/src/wp-includes/comment.php
index b3738c24ec9df..d7b15126910bd 100644
--- a/src/wp-includes/comment.php
+++ b/src/wp-includes/comment.php
@@ -2872,10 +2872,79 @@ function wp_update_comment_count( $post_id, $do_deferred = false ) {
 	return null;
 }
 
+/**
+ * Retrieves the comment types that are excluded from queries and counts by default.
+ *
+ * Applies the {@see 'default_excluded_comment_types'} filter and normalizes the
+ * result: non-scalar values are discarded, the rest are cast to strings, empties
+ * and duplicates are removed, and the special type tokens understood by
+ * WP_Comment_Query ('all', 'comment', 'comments', 'pings') are stripped - the
+ * filter deals in literal `comment_type` values only.
+ *
+ * @since 7.1.0
+ *
+ * @param WP_Comment_Query|null $query Optional. The current query instance when called
+ *                                     from WP_Comment_Query, or null in counting
+ *                                     contexts. Default null.
+ * @return string[] Comment types excluded by default.
+ */
+function wp_get_default_excluded_comment_types( $query = null ) {
+	/**
+	 * Filters the comment types that are excluded from query results by default.
+	 *
+	 * Comment types in this list are omitted from `WP_Comment_Query` results
+	 * unless the query explicitly requests the 'all' type, or explicitly
+	 * includes the specific type via the 'type' or 'type__in' query variables.
+	 *
+	 * This allows plugins to keep comment types out of standard comment
+	 * listings and counts by default, without having to filter every
+	 * query individually. The 'note' comment type, used by the editor, is
+	 * excluded by default. The same set is applied when recalculating a
+	 * post's stored comment count in wp_update_comment_count_now() and when
+	 * counting pending comments, so an excluded type does not inflate
+	 * get_comments_number().
+	 *
+	 * Values must be literal `comment_type` values as stored in the database;
+	 * the special type tokens understood by WP_Comment_Query ('all', 'comment',
+	 * 'comments', 'pings') are ignored, as are values that are not scalar.
+	 *
+	 * Register callbacks for this filter unconditionally (for example on
+	 * 'plugins_loaded' or 'init') rather than toggling them per call: query
+	 * results are cached against the comment `last_changed` key, which does not
+	 * account for this filter's output, so per-call toggling can serve stale
+	 * results from the cache.
+	 *
+	 * This exclusion is a default-visibility convenience, not an access-control
+	 * mechanism: callers can still retrieve excluded types explicitly (for
+	 * example with 'type' => 'all'), so do not rely on this filter to keep
+	 * comment data private. Enforce capability checks wherever the data is
+	 * displayed or exposed (for example over REST).
+	 *
+	 * @since 7.1.0
+	 *
+	 * @param string[]              $excluded_types Comment types excluded from query results by default.
+	 *                                              Default array contains the 'note' type.
+	 * @param WP_Comment_Query|null $query          The WP_Comment_Query instance, or null in counting
+	 *                                              contexts (recalculating a post's stored comment
+	 *                                              count, counting pending comments).
+	 */
+	$excluded_types = apply_filters( 'default_excluded_comment_types', array( 'note' ), $query );
+
+	// Drop values that cannot be cast to a string, so a stray object or array cannot error out.
+	$excluded_types = array_filter( (array) $excluded_types, 'is_scalar' );
+
+	$excluded_types = array_unique( array_filter( array_map( 'strval', $excluded_types ), 'strlen' ) );
+
+	// Strip the special type tokens so an alias cannot poison explicit-type queries.
+	return array_values( array_diff( $excluded_types, array( 'all', 'comment', 'comments', 'pings' ) ) );
+}
+
 /**
  * Updates the comment count for the post.
  *
  * @since 2.5.0
+ * @since 7.1.0 The excluded comment types are derived from the
+ *              {@see 'default_excluded_comment_types'} filter.
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
@@ -2914,7 +2983,26 @@ function wp_update_comment_count_now( $post_id ) {
 	$new = apply_filters( 'pre_wp_update_comment_count_now', null, $old, $post_id );
 
 	if ( is_null( $new ) ) {
-		$new = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->comments WHERE comment_post_ID = %d AND comment_approved = '1' AND comment_type != 'note'", $post_id ) );
+		$excluded_types = wp_get_default_excluded_comment_types();
+
+		if ( $excluded_types ) {
+			$new = (int) $wpdb->get_var(
+				$wpdb->prepare(
+					sprintf(
+						"SELECT COUNT(*) FROM $wpdb->comments WHERE comment_post_ID = %%d AND comment_approved = '1' AND comment_type NOT IN (%s)",
+						implode( ', ', array_fill( 0, count( $excluded_types ), '%s' ) )
+					),
+					array_merge( array( $post_id ), $excluded_types )
+				)
+			);
+		} else {
+			$new = (int) $wpdb->get_var(
+				$wpdb->prepare(
+					"SELECT COUNT(*) FROM $wpdb->comments WHERE comment_post_ID = %d AND comment_approved = '1'",
+					$post_id
+				)
+			);
+		}
 	} else {
 		$new = (int) $new;
 	}
diff --git a/tests/phpunit/tests/admin/includes/comment/GetPendingCommentsNum_Test.php b/tests/phpunit/tests/admin/includes/comment/GetPendingCommentsNum_Test.php
new file mode 100644
index 0000000000000..ef0059967a670
--- /dev/null
+++ b/tests/phpunit/tests/admin/includes/comment/GetPendingCommentsNum_Test.php
@@ -0,0 +1,137 @@
+<?php
+
+/**
+ * @group admin
+ * @group comment
+ *
+ * @covers ::get_pending_comments_num
+ */
+class Admin_Includes_Comment_GetPendingCommentsNum_Test extends WP_UnitTestCase {
+
+	/**
+	 * Creates a pending (unapproved) comment of a given type on a post.
+	 *
+	 * @param int    $post_id      Post to attach the comment to.
+	 * @param string $comment_type Comment type slug.
+	 * @return int The new comment ID.
+	 */
+	private function make_pending( $post_id, $comment_type = 'comment' ) {
+		return self::factory()->comment->create(
+			array(
+				'comment_post_ID'  => $post_id,
+				'comment_type'     => $comment_type,
+				'comment_approved' => '0',
+			)
+		);
+	}
+
+	/**
+	 * @ticket 65537
+	 */
+	public function test_counts_only_pending_comments() {
+		$post_id = self::factory()->post->create();
+		$this->make_pending( $post_id );
+		self::factory()->comment->create(
+			array(
+				'comment_post_ID'  => $post_id,
+				'comment_approved' => '1',
+			)
+		);
+
+		$this->assertSame( 1, get_pending_comments_num( $post_id ) );
+	}
+
+	/**
+	 * @ticket 65537
+	 */
+	public function test_excludes_note_type_by_default() {
+		$post_id = self::factory()->post->create();
+		$this->make_pending( $post_id );
+		$this->make_pending( $post_id, 'note' );
+
+		$this->assertSame( 1, get_pending_comments_num( $post_id ) );
+	}
+
+	/**
+	 * A type added to the excluded set must drop out of the pending count.
+	 *
+	 * @ticket 65537
+	 */
+	public function test_excludes_a_filtered_type() {
+		$post_id = self::factory()->post->create();
+		$this->make_pending( $post_id );
+		$this->make_pending( $post_id, 'review' );
+
+		// 'review' is counted by default.
+		$this->assertSame( 2, get_pending_comments_num( $post_id ) );
+
+		$filter = static function ( $types ) {
+			$types[] = 'review';
+			return $types;
+		};
+		add_filter( 'default_excluded_comment_types', $filter );
+		$num = get_pending_comments_num( $post_id );
+		remove_filter( 'default_excluded_comment_types', $filter );
+
+		$this->assertSame( 1, $num );
+	}
+
+	/**
+	 * The exclusion is filter-driven, not a hard-coded 'note' literal.
+	 *
+	 * @ticket 65537
+	 */
+	public function test_emptying_filter_counts_note_type() {
+		$post_id = self::factory()->post->create();
+		$this->make_pending( $post_id, 'note' );
+
+		$this->assertSame( 0, get_pending_comments_num( $post_id ) );
+
+		add_filter( 'default_excluded_comment_types', '__return_empty_array' );
+		$num = get_pending_comments_num( $post_id );
+		remove_filter( 'default_excluded_comment_types', '__return_empty_array' );
+
+		$this->assertSame( 1, $num );
+	}
+
+	/**
+	 * A filter callback returning false degrades gracefully to no exclusions.
+	 *
+	 * Scalar returns are cast to an array and treated as a single excluded type;
+	 * only values that normalize to an empty set disable the exclusions.
+	 *
+	 * @ticket 65537
+	 */
+	public function test_false_filter_return_counts_all_types() {
+		$post_id = self::factory()->post->create();
+		$this->make_pending( $post_id, 'note' );
+
+		add_filter( 'default_excluded_comment_types', '__return_false' );
+		$num = get_pending_comments_num( $post_id );
+		remove_filter( 'default_excluded_comment_types', '__return_false' );
+
+		$this->assertSame( 1, $num );
+	}
+
+	/**
+	 * @ticket 65537
+	 */
+	public function test_array_input_returns_counts_keyed_by_post() {
+		$post_a = self::factory()->post->create();
+		$post_b = self::factory()->post->create();
+		$this->make_pending( $post_a );
+		$this->make_pending( $post_a, 'note' );
+		$this->make_pending( $post_b );
+		$this->make_pending( $post_b );
+
+		$counts = get_pending_comments_num( array( $post_a, $post_b ) );
+
+		$this->assertSame(
+			array(
+				$post_a => 1,
+				$post_b => 2,
+			),
+			$counts
+		);
+	}
+}
diff --git a/tests/phpunit/tests/admin/wpCommentsListTable.php b/tests/phpunit/tests/admin/wpCommentsListTable.php
index 185bc5bfa48b0..3b9b6d35b482a 100644
--- a/tests/phpunit/tests/admin/wpCommentsListTable.php
+++ b/tests/phpunit/tests/admin/wpCommentsListTable.php
@@ -275,4 +275,108 @@ public function data_comment_type(): array {
 			'all type requested'             => array( 'all' ),
 		);
 	}
+
+	/**
+	 * A type added to the default-excluded set is not listed unless it is requested.
+	 *
+	 * The list table forces the default exclusions through 'type__not_in', so an
+	 * excluded type stays hidden even for a 'type=all' request.
+	 *
+	 * @ticket 65537
+	 *
+	 * @dataProvider data_unrequested_comment_type
+	 *
+	 * @param string $comment_type The comment_type request value to test.
+	 */
+	public function test_comments_list_table_hides_filtered_excluded_comment_type( string $comment_type ) {
+		$post_id = self::factory()->post->create();
+
+		self::factory()->comment->create(
+			array(
+				'comment_post_ID'  => $post_id,
+				'comment_type'     => 'private',
+				'comment_approved' => '1',
+			)
+		);
+
+		$regular_comment_id = self::factory()->comment->create(
+			array(
+				'comment_post_ID'  => $post_id,
+				'comment_type'     => '',
+				'comment_approved' => '1',
+			)
+		);
+
+		add_filter( 'default_excluded_comment_types', array( $this, 'filter_add_private_comment_type' ) );
+
+		$_REQUEST['comment_type'] = $comment_type;
+		$this->table->prepare_items();
+
+		$this->assertSame(
+			array( $regular_comment_id ),
+			array_map( 'intval', wp_list_pluck( $this->table->items, 'comment_ID' ) )
+		);
+	}
+
+	/**
+	 * Data provider for test_comments_list_table_hides_filtered_excluded_comment_type().
+	 *
+	 * @return array<string, string[]>
+	 */
+	public function data_unrequested_comment_type(): array {
+		return array(
+			'no type requested'  => array( '' ),
+			'all type requested' => array( 'all' ),
+		);
+	}
+
+	/**
+	 * A type added to the default-excluded set is listed when explicitly requested.
+	 *
+	 * A plugin can surface its own excluded type through the
+	 * 'admin_comment_types_dropdown' filter, so selecting it has to return results.
+	 *
+	 * @ticket 65537
+	 */
+	public function test_comments_list_table_shows_explicitly_requested_excluded_comment_type() {
+		$post_id = self::factory()->post->create();
+
+		$private_comment_id = self::factory()->comment->create(
+			array(
+				'comment_post_ID'  => $post_id,
+				'comment_type'     => 'private',
+				'comment_approved' => '1',
+			)
+		);
+
+		self::factory()->comment->create(
+			array(
+				'comment_post_ID'  => $post_id,
+				'comment_type'     => '',
+				'comment_approved' => '1',
+			)
+		);
+
+		add_filter( 'default_excluded_comment_types', array( $this, 'filter_add_private_comment_type' ) );
+
+		$_REQUEST['comment_type'] = 'private';
+		$this->table->prepare_items();
+
+		$this->assertSame(
+			array( $private_comment_id ),
+			array_map( 'intval', wp_list_pluck( $this->table->items, 'comment_ID' ) )
+		);
+	}
+
+	/**
+	 * Adds the 'private' comment type to the default-excluded set.
+	 *
+	 * @param string[] $excluded_types Comment types excluded by default.
+	 * @return string[] Filtered comment types.
+	 */
+	public function filter_add_private_comment_type( $excluded_types ): array {
+		$excluded_types[] = 'private';
+
+		return $excluded_types;
+	}
 }
diff --git a/tests/phpunit/tests/comment/query.php b/tests/phpunit/tests/comment/query.php
index dc870a78ae494..f591be9480219 100644
--- a/tests/phpunit/tests/comment/query.php
+++ b/tests/phpunit/tests/comment/query.php
@@ -5534,4 +5534,364 @@ public function test_get_comment_count_excludes_note_type() {
 		$this->assertSame( 1, $counts['all'] );
 		$this->assertSame( 1, $counts['total_comments'] );
 	}
+
+	/**
+	 * Helper method to create the standard set of comments used by the
+	 * `default_excluded_comment_types` filter tests.
+	 *
+	 * Creates one comment of each of the 'comment', 'note', and 'private' types.
+	 *
+	 * @since 7.1.0
+	 *
+	 * @return array<'comment'|'note'|'private', int> Array of created comment IDs keyed by type.
+	 */
+	protected function create_excluded_type_test_comments(): array {
+		return array(
+			'comment' => self::factory()->comment->create(
+				array(
+					'comment_post_ID'  => self::$post_id,
+					'comment_approved' => '1',
+				)
+			),
+			'note'    => self::factory()->comment->create(
+				array(
+					'comment_post_ID'  => self::$post_id,
+					'comment_approved' => '1',
+					'comment_type'     => 'note',
+				)
+			),
+			'private' => self::factory()->comment->create(
+				array(
+					'comment_post_ID'  => self::$post_id,
+					'comment_approved' => '1',
+					'comment_type'     => 'private',
+				)
+			),
+		);
+	}
+
+	/**
+	 * Returns the comment types for a list of comment IDs.
+	 *
+	 * @param int[] $comment_ids Comment IDs.
+	 * @return string[] Comment types.
+	 */
+	private function get_comment_types_for_ids( array $comment_ids ): array {
+		return array_map(
+			static function ( int $comment_id ): string {
+				return get_comment( $comment_id )->comment_type;
+			},
+			$comment_ids
+		);
+	}
+
+	/**
+	 * A custom comment type added through the filter is excluded by default,
+	 * alongside the default-excluded 'note' type.
+	 *
+	 * @ticket 65537
+	 * @covers WP_Comment_Query::get_comment_ids
+	 */
+	public function test_default_excluded_comment_types_filter_excludes_custom_type() {
+		$this->create_excluded_type_test_comments();
+
+		add_filter(
+			'default_excluded_comment_types',
+			static function ( array $types ): array {
+				$types[] = 'private';
+				return $types;
+			}
+		);
+
+		$query = new WP_Comment_Query();
+		$found = $query->query( array( 'fields' => 'ids' ) );
+
+		$this->assertSameSets(
+			array( 'comment' ),
+			$this->get_comment_types_for_ids( $found ),
+			'The custom excluded type and the default note type should both be omitted.'
+		);
+	}
+
+	/**
+	 * Removing 'note' from the filtered list makes notes appear in default queries,
+	 * proving the default exclusion itself is filterable.
+	 *
+	 * @ticket 65537
+	 * @covers WP_Comment_Query::get_comment_ids
+	 */
+	public function test_default_excluded_comment_types_filter_can_remove_note() {
+		$this->create_excluded_type_test_comments();
+
+		add_filter( 'default_excluded_comment_types', '__return_empty_array' );
+
+		$query = new WP_Comment_Query();
+		$found = $query->query( array( 'fields' => 'ids' ) );
+
+		$this->assertSameSets(
+			array( 'comment', 'note', 'private' ),
+			$this->get_comment_types_for_ids( $found ),
+			'With an empty exclusion list, all comment types should be returned.'
+		);
+	}
+
+	/**
+	 * A custom excluded type is still returned when explicitly requested.
+	 *
+	 * @ticket 65537
+	 * @covers WP_Comment_Query::get_comment_ids
+	 * @dataProvider data_default_excluded_comment_types_explicit_request
+	 *
+	 * @param array<string, string|array> $query_args     Query arguments for WP_Comment_Query.
+	 * @param string[]                    $expected_types Expected comment types.
+	 */
+	public function test_default_excluded_comment_types_filter_respects_explicit_request( array $query_args, array $expected_types ) {
+		$this->create_excluded_type_test_comments();
+
+		add_filter(
+			'default_excluded_comment_types',
+			static function ( array $types ): array {
+				$types[] = 'private';
+				return $types;
+			}
+		);
+
+		$query = new WP_Comment_Query();
+		$found = $query->query( array_merge( $query_args, array( 'fields' => 'ids' ) ) );
+
+		$this->assertSameSets( $expected_types, $this->get_comment_types_for_ids( $found ) );
+	}
+
+	/**
+	 * Data provider for explicit-request tests against a filtered excluded type.
+	 *
+	 * @since 7.1.0
+	 *
+	 * @return array<string, array{ query_args: array<string, string|array>, expected_types: string[] }>
+	 */
+	public function data_default_excluded_comment_types_explicit_request(): array {
+		return array(
+			'type all includes excluded types'      => array(
+				'query_args'     => array( 'type' => 'all' ),
+				'expected_types' => array( 'comment', 'note', 'private' ),
+			),
+			'explicit custom type'                  => array(
+				'query_args'     => array( 'type' => 'private' ),
+				'expected_types' => array( 'private' ),
+			),
+			'custom type via type__in'              => array(
+				'query_args'     => array( 'type__in' => array( 'private' ) ),
+				'expected_types' => array( 'private' ),
+			),
+			'custom type with comment via type__in' => array(
+				'query_args'     => array( 'type__in' => array( 'private', 'comment' ) ),
+				'expected_types' => array( 'private', 'comment' ),
+			),
+		);
+	}
+
+	/**
+	 * The filter receives the default 'note' type and the WP_Comment_Query instance.
+	 *
+	 * @ticket 65537
+	 * @covers WP_Comment_Query::get_comment_ids
+	 */
+	public function test_default_excluded_comment_types_filter_receives_default_and_instance() {
+		$filter_args = array();
+
+		add_filter(
+			'default_excluded_comment_types',
+			static function ( $types, $query ) use ( &$filter_args ) {
+				$filter_args = array( $types, $query );
+				return $types;
+			},
+			10,
+			2
+		);
+
+		$query = new WP_Comment_Query();
+		$query->query( array( 'fields' => 'ids' ) );
+
+		$this->assertSame( array( 'note' ), $filter_args[0], 'The filter should receive the default note type.' );
+		$this->assertInstanceOf( WP_Comment_Query::class, $filter_args[1], 'The filter should receive the query instance.' );
+	}
+
+	/**
+	 * A custom excluded type is only added once to the query, even when a query
+	 * already excludes it via type__not_in.
+	 *
+	 * @ticket 65537
+	 * @covers WP_Comment_Query::get_comment_ids
+	 */
+	public function test_default_excluded_comment_types_filter_not_duplicated_in_query() {
+		$this->create_excluded_type_test_comments();
+
+		add_filter(
+			'default_excluded_comment_types',
+			static function ( array $types ): array {
+				$types[] = 'private';
+				return $types;
+			}
+		);
+
+		$captured_where = '';
+		add_filter(
+			'comments_clauses',
+			static function ( array $clauses ) use ( &$captured_where ): array {
+				$captured_where = $clauses['where'];
+				return $clauses;
+			}
+		);
+
+		$query = new WP_Comment_Query();
+		$query->query(
+			array(
+				'type__not_in' => array( 'private' ),
+				'fields'       => 'ids',
+			)
+		);
+
+		$private_count = substr_count( $captured_where, "'private'" );
+		$this->assertSame( 1, $private_count, 'The private type should only appear once in the WHERE clause.' );
+	}
+
+	/**
+	 * A filter callback returning false degrades gracefully to no exclusions.
+	 *
+	 * Scalar returns are cast to an array and treated as a single excluded type;
+	 * only values that normalize to an empty set disable the exclusions.
+	 *
+	 * @ticket 65537
+	 * @covers WP_Comment_Query::get_comment_ids
+	 */
+	public function test_default_excluded_comment_types_filter_false_return_is_tolerated() {
+		$comments = $this->create_note_type_test_comments();
+
+		add_filter( 'default_excluded_comment_types', '__return_false' );
+
+		$query = new WP_Comment_Query();
+		$found = $query->query( array( 'fields' => 'ids' ) );
+
+		// With no exclusions, the note comment is included.
+		$this->assertContains( $comments['note'], $found );
+	}
+
+	/**
+	 * The special type tokens understood by WP_Comment_Query are stripped from the
+	 * filter output, so an alias cannot poison an explicit-type query.
+	 *
+	 * @ticket 65537
+	 * @covers ::wp_get_default_excluded_comment_types
+	 */
+	public function test_default_excluded_comment_types_filter_strips_special_tokens() {
+		$comments = $this->create_note_type_test_comments();
+
+		add_filter(
+			'default_excluded_comment_types',
+			static function ( array $types ): array {
+				// 'pings' is a WP_Comment_Query alias, not a literal comment type.
+				$types[] = 'pings';
+				return $types;
+			}
+		);
+
+		// An explicit request for pingbacks must still find them.
+		$query = new WP_Comment_Query();
+		$found = $query->query(
+			array(
+				'type'   => 'pingback',
+				'fields' => 'ids',
+			)
+		);
+
+		$this->assertSame( array( $comments['pingback'] ), array_map( 'intval', $found ) );
+
+		// The alias excludes nothing from a default query either.
+		$query = new WP_Comment_Query();
+		$found = $query->query( array( 'fields' => 'ids' ) );
+
+		$this->assertContains( $comments['pingback'], $found );
+	}
+
+	/**
+	 * A type requested via a query alias counts as an explicit request, so an
+	 * excluded literal type is still returned when its alias is requested.
+	 *
+	 * @ticket 65537
+	 * @covers WP_Comment_Query::get_comment_ids
+	 */
+	public function test_default_excluded_comment_types_filter_respects_alias_request() {
+		$comments = $this->create_note_type_test_comments();
+
+		add_filter(
+			'default_excluded_comment_types',
+			static function ( array $types ): array {
+				$types[] = 'pingback';
+				return $types;
+			}
+		);
+
+		// 'pings' is a query alias for the 'pingback' and 'trackback' types, so
+		// an explicit request for it must still return pingbacks.
+		$query = new WP_Comment_Query();
+		$found = $query->query(
+			array(
+				'type'   => 'pings',
+				'fields' => 'ids',
+			)
+		);
+
+		$this->assertContains( $comments['pingback'], $found );
+
+		// A default query, which does not request the type, still excludes it.
+		$query = new WP_Comment_Query();
+		$found = $query->query( array( 'fields' => 'ids' ) );
+
+		$this->assertNotContains( $comments['pingback'], $found );
+	}
+
+	/**
+	 * A comment type named '0' is preserved by the normalization rather than
+	 * being dropped as an empty value.
+	 *
+	 * @ticket 65537
+	 * @covers ::wp_get_default_excluded_comment_types
+	 */
+	public function test_default_excluded_comment_types_filter_preserves_zero_string_type() {
+		add_filter(
+			'default_excluded_comment_types',
+			static function ( array $types ): array {
+				$types[] = '0';
+				return $types;
+			}
+		);
+
+		$this->assertContains( '0', wp_get_default_excluded_comment_types() );
+	}
+
+	/**
+	 * Non-scalar values in the filter output are dropped rather than cast, so a
+	 * stray object or array does not error out.
+	 *
+	 * @ticket 65537
+	 * @covers ::wp_get_default_excluded_comment_types
+	 */
+	public function test_default_excluded_comment_types_filter_drops_non_scalar_values() {
+		add_filter(
+			'default_excluded_comment_types',
+			static function ( array $types ): array {
+				$types[] = new stdClass();
+				$types[] = array( 'nested' );
+				$types[] = null;
+				$types[] = 'private';
+				return $types;
+			}
+		);
+
+		$this->assertSame(
+			array( 'note', 'private' ),
+			wp_get_default_excluded_comment_types(),
+			'Only the scalar comment types should survive normalization.'
+		);
+	}
 }
diff --git a/tests/phpunit/tests/comment/wpUpdateCommentCountNow.php b/tests/phpunit/tests/comment/wpUpdateCommentCountNow.php
index 9dbb1f244ccf8..2b0d8e5eab4d0 100644
--- a/tests/phpunit/tests/comment/wpUpdateCommentCountNow.php
+++ b/tests/phpunit/tests/comment/wpUpdateCommentCountNow.php
@@ -83,6 +83,101 @@ public function test_only_approved_regular_comments_are_counted() {
 		$this->assertSame( '1', get_comments_number( $post_id ) );
 	}
 
+	/**
+	 * A comment type excluded via the shared filter must not inflate the stored count.
+	 *
+	 * @ticket 65537
+	 */
+	public function test_filtered_excluded_type_does_not_inflate_count() {
+		$post_id = self::factory()->post->create();
+
+		self::factory()->comment->create(
+			array(
+				'comment_post_ID'  => $post_id,
+				'comment_approved' => 1,
+			)
+		);
+		self::factory()->comment->create(
+			array(
+				'comment_post_ID'  => $post_id,
+				'comment_type'     => 'review',
+				'comment_approved' => 1,
+			)
+		);
+
+		// Without exclusion, both approved comments are counted.
+		$this->assertTrue( wp_update_comment_count_now( $post_id ) );
+		$this->assertSame( '2', get_comments_number( $post_id ) );
+
+		// Excluding 'review' through the same filter that hides it from queries drops it from the count.
+		$filter = static function ( $types ) {
+			$types[] = 'review';
+			return $types;
+		};
+		add_filter( 'default_excluded_comment_types', $filter );
+		$this->assertTrue( wp_update_comment_count_now( $post_id ) );
+		remove_filter( 'default_excluded_comment_types', $filter );
+
+		$this->assertSame( '1', get_comments_number( $post_id ) );
+	}
+
+	/**
+	 * The count is driven by the filtered set, not a hard-coded 'note' literal.
+	 *
+	 * Clearing the excluded set causes 'note' comments to be counted, proving the
+	 * exclusion comes from the filter rather than an in-query literal.
+	 *
+	 * @ticket 65537
+	 */
+	public function test_emptying_filter_counts_otherwise_excluded_types() {
+		$post_id = self::factory()->post->create();
+
+		self::factory()->comment->create(
+			array(
+				'comment_post_ID'  => $post_id,
+				'comment_type'     => 'note',
+				'comment_approved' => 1,
+			)
+		);
+
+		// By default the 'note' type is excluded.
+		$this->assertTrue( wp_update_comment_count_now( $post_id ) );
+		$this->assertSame( '0', get_comments_number( $post_id ) );
+
+		// A plugin that clears the excluded set causes notes to be counted.
+		add_filter( 'default_excluded_comment_types', '__return_empty_array' );
+		$this->assertTrue( wp_update_comment_count_now( $post_id ) );
+		remove_filter( 'default_excluded_comment_types', '__return_empty_array' );
+
+		$this->assertSame( '1', get_comments_number( $post_id ) );
+	}
+
+	/**
+	 * A filter callback returning false degrades gracefully to no exclusions.
+	 *
+	 * Scalar returns are cast to an array and treated as a single excluded type;
+	 * only values that normalize to an empty set disable the exclusions.
+	 *
+	 * @ticket 65537
+	 */
+	public function test_false_filter_return_counts_all_types() {
+		$post_id = self::factory()->post->create();
+
+		self::factory()->comment->create(
+			array(
+				'comment_post_ID'  => $post_id,
+				'comment_type'     => 'note',
+				'comment_approved' => 1,
+			)
+		);
+
+		add_filter( 'default_excluded_comment_types', '__return_false' );
+		$this->assertTrue( wp_update_comment_count_now( $post_id ) );
+		remove_filter( 'default_excluded_comment_types', '__return_false' );
+
+		$this->assertSame( '1', get_comments_number( $post_id ) );
+	}
+
 	public function _return_100() {
 		return 100;
 	}