diff --git a/changelog.d/19429.removal b/changelog.d/19429.removal
new file mode 100644
index 0000000000..b52ca2423d
--- /dev/null
+++ b/changelog.d/19429.removal
@@ -0,0 +1 @@
+Remove support for [MSC3244: Room version capabilities](https://github.com/matrix-org/matrix-spec-proposals/pull/3244) as the MSC was rejected.
\ No newline at end of file
diff --git a/synapse/api/room_versions.py b/synapse/api/room_versions.py
index 97dac661a3..2f98d7a8a8 100644
--- a/synapse/api/room_versions.py
+++ b/synapse/api/room_versions.py
@@ -18,7 +18,6 @@
 #
 #
 
-from typing import Callable
 
 import attr
 
@@ -496,40 +495,3 @@ KNOWN_ROOM_VERSIONS: dict[str, RoomVersion] = {
         RoomVersions.HydraV11,
     )
 }
-
-
-@attr.s(slots=True, frozen=True, auto_attribs=True)
-class RoomVersionCapability:
-    """An object which describes the unique attributes of a room version."""
-
-    identifier: str  # the identifier for this capability
-    preferred_version: RoomVersion | None
-    support_check_lambda: Callable[[RoomVersion], bool]
-
-
-MSC3244_CAPABILITIES = {
-    cap.identifier: {
-        "preferred": (
-            cap.preferred_version.identifier
-            if cap.preferred_version is not None
-            else None
-        ),
-        "support": [
-            v.identifier
-            for v in KNOWN_ROOM_VERSIONS.values()
-            if cap.support_check_lambda(v)
-        ],
-    }
-    for cap in (
-        RoomVersionCapability(
-            "knock",
-            RoomVersions.V7,
-            lambda room_version: room_version.knock_join_rule,
-        ),
-        RoomVersionCapability(
-            "restricted",
-            RoomVersions.V9,
-            lambda room_version: room_version.restricted_join_rule,
-        ),
-    )
-}
diff --git a/synapse/config/experimental.py b/synapse/config/experimental.py
index 1bd70ead09..9b6ff482cf 100644
--- a/synapse/config/experimental.py
+++ b/synapse/config/experimental.py
@@ -385,9 +385,6 @@ class ExperimentalConfig(Config):
         # MSC3814 (dehydrated devices with SSSS)
         self.msc3814_enabled: bool = experimental.get("msc3814_enabled", False)
 
-        # MSC3244 (room version capabilities)
-        self.msc3244_enabled: bool = experimental.get("msc3244_enabled", True)
-
         # MSC3266 (room summary api)
         self.msc3266_enabled: bool = experimental.get("msc3266_enabled", False)
 
diff --git a/synapse/rest/client/capabilities.py b/synapse/rest/client/capabilities.py
index baff999ab0..705d74dee1 100644
--- a/synapse/rest/client/capabilities.py
+++ b/synapse/rest/client/capabilities.py
@@ -21,7 +21,7 @@ import logging
 from http import HTTPStatus
 from typing import TYPE_CHECKING
 
-from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, MSC3244_CAPABILITIES
+from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 from synapse.http.server import HttpServer
 from synapse.http.servlet import RestServlet
 from synapse.http.site import SynapseRequest
@@ -77,11 +77,6 @@ class CapabilitiesRestServlet(RestServlet):
             }
         }
 
-        if self.config.experimental.msc3244_enabled:
-            response["capabilities"]["m.room_versions"][
-                "org.matrix.msc3244.room_capabilities"
-            ] = MSC3244_CAPABILITIES
-
         if self.config.experimental.msc3720_enabled:
             response["capabilities"]["org.matrix.msc3720.account_status"] = {
                 "enabled": True,
diff --git a/tests/rest/client/test_capabilities.py b/tests/rest/client/test_capabilities.py
index 0eec313061..2567fee2a4 100644
--- a/tests/rest/client/test_capabilities.py
+++ b/tests/rest/client/test_capabilities.py
@@ -209,46 +209,6 @@ class CapabilitiesTestCase(unittest.HomeserverTestCase):
         self.assertEqual(channel.code, HTTPStatus.OK)
         self.assertFalse(capabilities["m.3pid_changes"]["enabled"])
 
-    @override_config({"experimental_features": {"msc3244_enabled": False}})
-    def test_get_does_not_include_msc3244_fields_when_disabled(self) -> None:
-        access_token = self.get_success(
-            self.auth_handler.create_access_token_for_user_id(
-                self.user, device_id=None, valid_until_ms=None
-            )
-        )
-
-        channel = self.make_request("GET", self.url, access_token=access_token)
-        capabilities = channel.json_body["capabilities"]
-
-        self.assertEqual(channel.code, 200)
-        self.assertNotIn(
-            "org.matrix.msc3244.room_capabilities", capabilities["m.room_versions"]
-        )
-
-    def test_get_does_include_msc3244_fields_when_enabled(self) -> None:
-        access_token = self.get_success(
-            self.auth_handler.create_access_token_for_user_id(
-                self.user, device_id=None, valid_until_ms=None
-            )
-        )
-
-        channel = self.make_request("GET", self.url, access_token=access_token)
-        capabilities = channel.json_body["capabilities"]
-
-        self.assertEqual(channel.code, 200)
-        for details in capabilities["m.room_versions"][
-            "org.matrix.msc3244.room_capabilities"
-        ].values():
-            if details["preferred"] is not None:
-                self.assertTrue(
-                    details["preferred"] in KNOWN_ROOM_VERSIONS,
-                    str(details["preferred"]),
-                )
-
-            self.assertGreater(len(details["support"]), 0)
-            for room_version in details["support"]:
-                self.assertTrue(room_version in KNOWN_ROOM_VERSIONS, str(room_version))
-
     def test_get_get_token_login_fields_when_disabled(self) -> None:
         """By default login via an existing session is disabled."""
         access_token = self.get_success(