diff --git a/.gitignore b/.gitignore
index c18dd8d..36626b5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
 __pycache__/
+dist/
+*.egg-info/
diff --git a/src/colony_sdk/client.py b/src/colony_sdk/client.py
index 4eb83e8..e5e3915 100644
--- a/src/colony_sdk/client.py
+++ b/src/colony_sdk/client.py
@@ -233,12 +233,27 @@ def delete_post(self, post_id: str) -> dict:
 
     # ── Comments ─────────────────────────────────────────────────────
 
-    def create_comment(self, post_id: str, body: str) -> dict:
-        """Comment on a post."""
+    def create_comment(
+        self,
+        post_id: str,
+        body: str,
+        parent_id: str | None = None,
+    ) -> dict:
+        """Comment on a post, optionally as a reply to another comment.
+
+        Args:
+            post_id: The post to comment on.
+            body: Comment text.
+            parent_id: If set, this comment is a reply to the comment
+                with this ID (threaded comments).
+        """
+        payload: dict[str, str] = {"body": body, "client": "colony-sdk-python"}
+        if parent_id:
+            payload["parent_id"] = parent_id
         return self._raw_request(
             "POST",
             f"/posts/{post_id}/comments",
-            body={"body": body, "client": "colony-sdk-python"},
+            body=payload,
         )
 
     def get_comments(self, post_id: str, page: int = 1) -> dict:
diff --git a/tests/test_api_methods.py b/tests/test_api_methods.py
index f1034f6..6ef9b2a 100644
--- a/tests/test_api_methods.py
+++ b/tests/test_api_methods.py
@@ -391,6 +391,26 @@ def test_create_comment_payload(self, mock_urlopen: MagicMock) -> None:
         body = _last_body(mock_urlopen)
         assert body == {"body": "Nice post!", "client": "colony-sdk-python"}
 
+    @patch("colony_sdk.client.urlopen")
+    def test_create_comment_with_parent_id(self, mock_urlopen: MagicMock) -> None:
+        mock_urlopen.return_value = _mock_response({"id": "c2"})
+        client = _authed_client()
+
+        client.create_comment("post-1", "I agree!", parent_id="c1")
+
+        body = _last_body(mock_urlopen)
+        assert body == {"body": "I agree!", "client": "colony-sdk-python", "parent_id": "c1"}
+
+    @patch("colony_sdk.client.urlopen")
+    def test_create_comment_without_parent_id(self, mock_urlopen: MagicMock) -> None:
+        mock_urlopen.return_value = _mock_response({"id": "c3"})
+        client = _authed_client()
+
+        client.create_comment("post-1", "Top-level comment")
+
+        body = _last_body(mock_urlopen)
+        assert "parent_id" not in body
+
     @patch("colony_sdk.client.urlopen")
     def test_get_comments(self, mock_urlopen: MagicMock) -> None:
         mock_urlopen.return_value = _mock_response({"comments": [], "total": 0})