diff --git a/tensorflow_quantum/core/serialize/serializer.py b/tensorflow_quantum/core/serialize/serializer.py
index 323e70025..b38f199b3 100644
--- a/tensorflow_quantum/core/serialize/serializer.py
+++ b/tensorflow_quantum/core/serialize/serializer.py
@@ -30,6 +30,17 @@
 _CONSTANT_TRUE = lambda x: True
 
 
+def _single_qubit_channel_check(x):
+    """Check that a noise channel operates on exactly one qubit."""
+    if len(x.qubits) != 1:
+        raise ValueError(
+            "Multi-qubit noise channels are not supported in TFQ. "
+            f"Got {x} acting on {len(x.qubits)} qubits. "
+            "Consider decomposing into single-qubit channels applied "
+            "via .on_each().")
+    return True
+
+
 def _round(x):
     return np.round(x, 6) if isinstance(x, float) else x
 
@@ -196,7 +207,7 @@ def _asymmetric_depolarize_serializer():
         gate_type=cirq.AsymmetricDepolarizingChannel,
         serialized_gate_id="ADP",
         args=args,
-        can_serialize_predicate=_CONSTANT_TRUE)
+        can_serialize_predicate=_single_qubit_channel_check)
 
 
 def _asymmetric_depolarize_deserializer():
@@ -234,7 +245,7 @@ def _depolarize_channel_serializer():
         gate_type=cirq.DepolarizingChannel,
         serialized_gate_id="DP",
         args=args,
-        can_serialize_predicate=_CONSTANT_TRUE)
+        can_serialize_predicate=_single_qubit_channel_check)
 
 
 def _depolarize_channel_deserializer():
@@ -272,7 +283,7 @@ def _gad_channel_serializer():
         gate_type=cirq.GeneralizedAmplitudeDampingChannel,
         serialized_gate_id="GAD",
         args=args,
-        can_serialize_predicate=_CONSTANT_TRUE)
+        can_serialize_predicate=_single_qubit_channel_check)
 
 
 def _gad_channel_deserializer():
@@ -309,7 +320,7 @@ def _amplitude_damp_channel_serializer():
         gate_type=cirq.AmplitudeDampingChannel,
         serialized_gate_id="AD",
         args=args,
-        can_serialize_predicate=_CONSTANT_TRUE)
+        can_serialize_predicate=_single_qubit_channel_check)
 
 
 def _amplitude_damp_channel_deserializer():
@@ -341,7 +352,7 @@ def _reset_channel_serializer():
         gate_type=cirq.ResetChannel,
         serialized_gate_id="RST",
         args=args,
-        can_serialize_predicate=_CONSTANT_TRUE)
+        can_serialize_predicate=_single_qubit_channel_check)
 
 
 def _reset_channel_deserializer():
@@ -370,7 +381,7 @@ def _phase_damp_channel_serializer():
         gate_type=cirq.PhaseDampingChannel,
         serialized_gate_id="PD",
         args=args,
-        can_serialize_predicate=_CONSTANT_TRUE)
+        can_serialize_predicate=_single_qubit_channel_check)
 
 
 def _phase_damp_channel_deserializer():
@@ -403,7 +414,7 @@ def _phase_flip_channel_serializer():
         gate_type=cirq.PhaseFlipChannel,
         serialized_gate_id="PF",
         args=args,
-        can_serialize_predicate=_CONSTANT_TRUE)
+        can_serialize_predicate=_single_qubit_channel_check)
 
 
 def _phase_flip_channel_deserializer():
@@ -437,7 +448,7 @@ def _bit_flip_channel_serializer():
         gate_type=cirq.BitFlipChannel,
         serialized_gate_id="BF",
         args=args,
-        can_serialize_predicate=_CONSTANT_TRUE)
+        can_serialize_predicate=_single_qubit_channel_check)
 
 
 def _bit_flip_channel_deserializer():
diff --git a/tensorflow_quantum/core/serialize/serializer_test.py b/tensorflow_quantum/core/serialize/serializer_test.py
index 3a89a03ea..e0d2e4a36 100644
--- a/tensorflow_quantum/core/serialize/serializer_test.py
+++ b/tensorflow_quantum/core/serialize/serializer_test.py
@@ -720,6 +720,16 @@ def test_serialize_noise_channel_unsupported_value(self):
         with self.assertRaises(ValueError):
             serializer.serialize_circuit(simple_circuit)
 
+    def test_serialize_multi_qubit_noise_channel(self):
+        """Ensure multi-qubit noise channels are rejected with clear error."""
+        q0 = cirq.GridQubit(0, 0)
+        q1 = cirq.GridQubit(0, 1)
+        multi_qubit_circuit = cirq.Circuit(
+            cirq.DepolarizingChannel(p=0.1, n_qubits=2)(q0, q1))
+        with self.assertRaisesRegex(ValueError,
+                                    "Multi-qubit noise channels"):
+            serializer.serialize_circuit(multi_qubit_circuit)
+
     @parameterized.parameters([{'inp': v} for v in ['wrong', 1.0, None, []]])
     def test_serialize_circuit_wrong_type(self, inp):
         """Attempt to serialize invalid objects types."""