diff --git a/templates/zerver/help/include/rest-endpoints.md b/templates/zerver/help/include/rest-endpoints.md
index f6cde3b639..8f9943a2e5 100644
--- a/templates/zerver/help/include/rest-endpoints.md
+++ b/templates/zerver/help/include/rest-endpoints.md
@@ -29,6 +29,7 @@
 * [Archive a stream](/api/archive-stream)
 * [Get topics in a stream](/api/get-stream-topics)
 * [Topic muting](/api/mute-topic)
+* [Delete a topic](/api/delete-topic)
 
 #### Users
 
diff --git a/zerver/openapi/python_examples.py b/zerver/openapi/python_examples.py
index 7e01549bc4..0d1d41e33d 100644
--- a/zerver/openapi/python_examples.py
+++ b/zerver/openapi/python_examples.py
@@ -499,6 +499,23 @@ def archive_stream(client: Client, stream_id: int) -> None:
     assert result["result"] == "success"
 
 
+@openapi_test_function("/streams/{stream_id}/delete_topic:post")
+def delete_topic(client: Client, stream_id: int, topic: str) -> None:
+
+    # {code_example|start}
+    # Delete a topic given its stream_id
+    request = {
+        "topic_name": topic,
+    }
+    result = client.call_endpoint(
+        url=f"/streams/{stream_id}/delete_topic", method="POST", request=request
+    )
+    # {code_example|end}
+    validate_against_openapi_schema(result, "/streams/{stream_id}/delete_topic", "post", "200")
+
+    assert result["result"] == "success"
+
+
 @openapi_test_function("/streams:get")
 def get_streams(client: Client) -> None:
 
@@ -1505,6 +1522,7 @@ def test_streams(client: Client, nonadmin_client: Client) -> None:
     toggle_mute_topic(client)
     update_subscription_settings(client)
     get_stream_topics(client, 1)
+    delete_topic(client, 1, "test")
     archive_stream(client, stream_id)
 
     test_user_not_authorized_error(nonadmin_client)
diff --git a/zerver/openapi/zulip.yaml b/zerver/openapi/zulip.yaml
index 82a918dcec..a9e58dc0ec 100644
--- a/zerver/openapi/zulip.yaml
+++ b/zerver/openapi/zulip.yaml
@@ -10755,6 +10755,54 @@ paths:
                         "result": "error",
                       }
                     description: An example JSON response for when the supplied stream does not exist
+  /streams/{stream_id}/delete_topic:
+    post:
+      operationId: delete-topic
+      summary: Delete a topic
+      tags: ["streams"]
+      description: |
+        Delete all messages in a topic.
+
+        `POST {{ api_url }}/v1/streams/{stream_id}/delete_topic`
+
+        Topics are a field on messages (not an independent
+        data structure), so deleting all the messages in the topic
+        deletes the topic from Zulip.
+      parameters:
+        - $ref: "#/components/parameters/StreamIdInPath"
+        - name: topic_name
+          in: query
+          description: |
+            The name of the topic to delete.
+          schema:
+            type: string
+          example: new coffee machine
+          required: true
+      responses:
+        "200":
+          description: Success.
+          content:
+            application/json:
+              schema:
+                allOf:
+                  - $ref: "#/components/schemas/JsonSuccess"
+                  - $ref: "#/components/schemas/SuccessDescription"
+        "400":
+          description: Error.
+          content:
+            application/json:
+              schema:
+                allOf:
+                  - $ref: "#/components/schemas/JsonError"
+                  - example:
+                      {
+                        "result": "error",
+                        "msg": "Must be an organization administrator",
+                        "code": "UNAUTHORIZED_PRINCIPAL",
+                      }
+                    description: |
+                      Error when the user does not have permission
+                      to delete topics in this organization.
   /typing:
     post:
       operationId: set-typing-status
diff --git a/zerver/tests/test_openapi.py b/zerver/tests/test_openapi.py
index c06d2c2061..254b06b8f4 100644
--- a/zerver/tests/test_openapi.py
+++ b/zerver/tests/test_openapi.py
@@ -208,7 +208,6 @@ class OpenAPIArgumentsTest(ZulipTestCase):
         #### TODO: These endpoints are a priority to document:
         "/realm/presence",
         "/streams/{stream_id}/members",
-        "/streams/{stream_id}/delete_topic",
         "/users/me/presence",
         "/users/me/alert_words",
         "/users/me/status",
diff --git a/zerver/views/streams.py b/zerver/views/streams.py
index db38b1d4c7..fcfe9abdf6 100644
--- a/zerver/views/streams.py
+++ b/zerver/views/streams.py
@@ -751,7 +751,7 @@ def get_topics_backend(
 def delete_in_topic(
     request: HttpRequest,
     user_profile: UserProfile,
-    stream_id: int = REQ(converter=to_non_negative_int),
+    stream_id: int = REQ(converter=to_non_negative_int, path_only=True),
     topic_name: str = REQ("topic_name"),
 ) -> HttpResponse:
     (stream, sub) = access_stream_by_id(user_profile, stream_id)