diff --git a/README.md b/README.md
index 679ed66..1ab7535 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,8 @@ extensions = [
 ## Options
 These values are placed in the conf.py of your sphinx project.
 
+Users hosting documentation on Read The Docs *do not* need to set any of the following unless custom configuration is wanted. The extension will automatically retrieve your site url.
+
 * `ogp_site_url`
     * This config option is very important, set it to the URL the site is being hosted on. 
 * `ogp_description_length`
diff --git a/docs/source/conf.py b/docs/source/conf.py
index 46f901f..ee638f3 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -12,17 +12,18 @@
 #
 import os
 import sys
-sys.path.insert(0, os.path.abspath('../..'))
+
+sys.path.insert(0, os.path.abspath("../.."))
 
 
 # -- Project information -----------------------------------------------------
 
-project = 'sphinxext-opengraph'
-copyright = '2020, FIRST'
-author = 'WPILib'
+project = "sphinxext-opengraph"
+copyright = "2020, FIRST"
+author = "WPILib"
 
 # The full version, including alpha/beta/rc tags
-release = '1.0'
+release = "1.0"
 
 
 # -- General configuration ---------------------------------------------------
@@ -36,7 +37,7 @@
 ]
 
 # Add any paths that contain templates here, relative to this directory.
-templates_path = ['_templates']
+templates_path = ["_templates"]
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
@@ -49,4 +50,4 @@
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 #
-html_theme = 'furo'
+html_theme = "furo"
diff --git a/output.txt b/output.txt
new file mode 100644
index 0000000..9fe0e6e
Binary files /dev/null and b/output.txt differ
diff --git a/sphinxext/opengraph/__init__.py b/sphinxext/opengraph/__init__.py
index 03c57a8..74cb70c 100644
--- a/sphinxext/opengraph/__init__.py
+++ b/sphinxext/opengraph/__init__.py
@@ -1,13 +1,17 @@
 from typing import Any, Dict
-from urllib.parse import urljoin
-from pathlib import Path
+from urllib.parse import urljoin, urlparse, urlunparse
+from pathlib import Path, PosixPath
 
 import docutils.nodes as nodes
 from sphinx.application import Sphinx
+from sphinx.util import logger
 
 from .descriptionparser import get_description
 from .titleparser import get_title
 
+import os
+
+
 DEFAULT_DESCRIPTION_LENGTH = 200
 
 # A selection from https://www.iana.org/assignments/media-types/media-types.xhtml#image
@@ -30,7 +34,10 @@ def make_tag(property: str, content: str) -> str:
 
 
 def get_tags(
-    context: Dict[str, Any], doctree: nodes.document, config: Dict[str, Any]
+    app: Sphinx,
+    context: Dict[str, Any],
+    doctree: nodes.document,
+    config: Dict[str, Any],
 ) -> str:
 
     # Set length of description
@@ -53,6 +60,24 @@ def get_tags(
 
     # type tag
     tags += make_tag("og:type", config["ogp_type"])
+    if os.getenv("READTHEDOCS") and config["ogp_site_url"] is None:
+        # readthedocs uses html_baseurl for sphinx > 1.8
+        parse_result = urlparse(config["html_baseurl"])
+
+        if config["html_baseurl"] is None:
+            raise EnvironmentError("ReadTheDocs did not provide a valid canonical URL!")
+
+        # Grab root url from canonical url
+        config["ogp_site_url"] = urlunparse(
+            (
+                parse_result.scheme,
+                parse_result.netloc,
+                parse_result.path,
+                "",
+                "",
+                "",
+            )
+        )
 
     # url tag
     # Get the URL of the specific page
@@ -109,7 +134,7 @@ def html_page_context(
     doctree: nodes.document,
 ) -> None:
     if doctree:
-        context["metatags"] += get_tags(context, doctree, app.config)
+        context["metatags"] += get_tags(app, context, doctree, app.config)
 
 
 def setup(app: Sphinx) -> Dict[str, Any]:
diff --git a/tests/conftest.py b/tests/conftest.py
index e0d15b3..913e5bc 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -2,6 +2,9 @@
 from bs4 import BeautifulSoup
 from sphinx.testing.path import path
 
+from sphinx.application import Sphinx
+
+
 pytest_plugins = "sphinx.testing.fixtures"
 
 
@@ -21,6 +24,12 @@ def _meta_tags(content):
     return BeautifulSoup(c, "html.parser").find_all("meta")
 
 
+def _og_meta_tags(content):
+    return [
+        tag for tag in _meta_tags(content) if tag.get("property", "").startswith("og:")
+    ]
+
+
 @pytest.fixture()
 def meta_tags(content):
     return _meta_tags(content)
diff --git a/tests/roots/test-rtd-default/conf.py b/tests/roots/test-rtd-default/conf.py
new file mode 100644
index 0000000..7f99bb3
--- /dev/null
+++ b/tests/roots/test-rtd-default/conf.py
@@ -0,0 +1,6 @@
+extensions = ["sphinxext.opengraph"]
+
+master_doc = "index"
+exclude_patterns = ["_build"]
+
+html_theme = "basic"
diff --git a/tests/roots/test-rtd-default/index.rst b/tests/roots/test-rtd-default/index.rst
new file mode 100644
index 0000000..634fe79
--- /dev/null
+++ b/tests/roots/test-rtd-default/index.rst
@@ -0,0 +1,8 @@
+* Item 1
+* Item 2
+
+    * Nested Item 1
+    * Nested Item 2
+    
+* Item 3
+* Item 4
\ No newline at end of file
diff --git a/tests/roots/test-rtd-invalid/conf.py b/tests/roots/test-rtd-invalid/conf.py
new file mode 100644
index 0000000..7f99bb3
--- /dev/null
+++ b/tests/roots/test-rtd-invalid/conf.py
@@ -0,0 +1,6 @@
+extensions = ["sphinxext.opengraph"]
+
+master_doc = "index"
+exclude_patterns = ["_build"]
+
+html_theme = "basic"
diff --git a/tests/roots/test-rtd-invalid/index.rst b/tests/roots/test-rtd-invalid/index.rst
new file mode 100644
index 0000000..634fe79
--- /dev/null
+++ b/tests/roots/test-rtd-invalid/index.rst
@@ -0,0 +1,8 @@
+* Item 1
+* Item 2
+
+    * Nested Item 1
+    * Nested Item 2
+    
+* Item 3
+* Item 4
\ No newline at end of file
diff --git a/tests/test_options.py b/tests/test_options.py
index 81b0995..f6439ae 100644
--- a/tests/test_options.py
+++ b/tests/test_options.py
@@ -1,4 +1,7 @@
 import pytest
+from sphinx.application import Sphinx
+import conftest
+import os
 
 
 def get_tag(tags, tag_type):
@@ -122,3 +125,36 @@ def test_skip_raw(og_meta_tags):
         description
         == "This text should be included. This text should also be included."
     )
+
+
+# use same as simple, as configuration is identical to overriden
+@pytest.mark.sphinx("html", testroot="simple")
+def test_rtd_override(app: Sphinx, monkeypatch):
+    monkeypatch.setenv("READTHEDOCS", "True")
+    app.config.html_baseurl = "https://failure.com"
+
+    app.build()
+    tags = conftest._og_meta_tags(app)
+
+    assert get_tag_content(tags, "url") == "http://example.org/index.html"
+
+
+@pytest.mark.sphinx("html", testroot="rtd-default")
+def test_rtd_valid(app: Sphinx, monkeypatch):
+    monkeypatch.setenv("READTHEDOCS", "True")
+    app.config.html_baseurl = "https://failure.com"
+
+    app.build()
+    tags = conftest._og_meta_tags(app)
+
+    assert get_tag_content(tags, "url") == "https://failure.com/index.html"
+
+
+# use rtd-default, as we are not changing configuration, but RTD variables
+@pytest.mark.sphinx("html", testroot="rtd-invalid")
+def test_rtd_invalid(app: Sphinx, monkeypatch):
+    monkeypatch.setenv("READTHEDOCS", "True")
+    app.config.html_baseurl = None
+
+    with pytest.raises(Exception):
+        app.build()