diff --git a/src/phoenix/server/api/routers/evaluation_handler.py b/src/phoenix/server/api/routers/evaluation_handler.py
index bddf3d6bf9..08af30d2cc 100644
--- a/src/phoenix/server/api/routers/evaluation_handler.py
+++ b/src/phoenix/server/api/routers/evaluation_handler.py
@@ -27,6 +27,7 @@ class EvaluationHandler(HTTPEndpoint):
 
     async def post(self, request: Request) -> Response:
         content_type = request.headers.get("content-type")
+        project_name = request.headers.get("project-name", DEFAULT_PROJECT_NAME)
         if content_type == "application/x-pandas-arrow":
             return await self._process_pyarrow(request)
         if content_type != "application/x-protobuf":
@@ -51,7 +52,7 @@ async def post(self, request: Request) -> Response:
                 content="Request body is invalid",
                 status_code=HTTP_422_UNPROCESSABLE_ENTITY,
             )
-        self.traces.put(evaluation)
+        self.traces.put(evaluation, project_name=project_name)
         return Response()
 
     async def get(self, request: Request) -> Response:
diff --git a/src/phoenix/session/client.py b/src/phoenix/session/client.py
index 72c71507cf..870a101d8e 100644
--- a/src/phoenix/session/client.py
+++ b/src/phoenix/session/client.py
@@ -140,16 +140,19 @@ def _warn_if_phoenix_is_not_running(self) -> None:
                 f"with `import phoenix as px; px.launch_app()`"
             )
 
-    def log_evaluations(self, *evals: Evaluations) -> None:
+    def log_evaluations(self, *evals: Evaluations, project_name: Optional[str] = None) -> None:
         for evaluation in evals:
             table = evaluation.to_pyarrow_table()
             sink = pa.BufferOutputStream()
+            headers = {"content-type": "application/x-pandas-arrow"}
+            if project_name:
+                headers["project-name"] = project_name
             with pa.ipc.new_stream(sink, table.schema) as writer:
                 writer.write_table(table)
             self._session.post(
                 urljoin(self._base_url, "/v1/evaluations"),
                 data=cast(bytes, sink.getvalue().to_pybytes()),
-                headers={"content-type": "application/x-pandas-arrow"},
+                headers=headers,
             ).raise_for_status()