diff --git a/openrag/services/orchestrators/partition_service.py b/openrag/services/orchestrators/partition_service.py
index b0204a9e4..68a56c843 100644
--- a/openrag/services/orchestrators/partition_service.py
+++ b/openrag/services/orchestrators/partition_service.py
@@ -674,7 +674,11 @@ def _meta(row: dict[str, Any]) -> dict[str, Any]:
 
     async def list_members(self, partition: str) -> list[dict]:
         await self._ensure_partition(partition)
-        return await self._membership_repo.list_partition_members(partition)
+        members = await self._membership_repo.list_partition_members(partition)
+        users = await asyncio.gather(*(self._user_repo.get_user(m["user_id"]) for m in members))
+        for member, user in zip(members, users, strict=True):
+            member["display_name"] = user.display_name if user else None
+        return members
 
     async def add_member(self, partition: str, user_id: int, role: str) -> None:
         await self._ensure_partition(partition)
diff --git a/tests/unit/services/orchestrators/test_partition_service.py b/tests/unit/services/orchestrators/test_partition_service.py
index ca2497aeb..ba26bc055 100644
--- a/tests/unit/services/orchestrators/test_partition_service.py
+++ b/tests/unit/services/orchestrators/test_partition_service.py
@@ -212,12 +212,18 @@ async def query_chunks_by_filter(self, collection, filters, output_fields=None):
 
 
 class FakeUserRepo:
-    def __init__(self, existing: set[int] | None = None):
+    def __init__(self, existing: set[int] | None = None, display_names: dict[int, str] | None = None):
         self._existing = existing if existing is not None else set()
+        self._display_names = display_names or {}
 
     async def user_exists(self, user_id: int) -> bool:
         return user_id in self._existing
 
+    async def get_user(self, user_id: int):
+        if user_id not in self._existing:
+            return None
+        return SimpleNamespace(display_name=self._display_names.get(user_id))
+
 
 def _svc(
     *,
@@ -830,6 +836,24 @@ async def test_list_members_missing_partition_404():
         await _svc(prepo=FakePartitionRepo(set())).list_members("x")
 
 
+@pytest.mark.asyncio
+async def test_list_members_enriches_with_display_name():
+    mrepo = FakeMembershipRepo(members={(9, "p")})
+    urepo = FakeUserRepo({9}, display_names={9: "Alice"})
+    svc = _svc(prepo=FakePartitionRepo({"p"}), mrepo=mrepo, urepo=urepo)
+    members = await svc.list_members("p")
+    assert members == [{"user_id": 9, "role": "viewer", "display_name": "Alice"}]
+
+
+@pytest.mark.asyncio
+async def test_list_members_missing_user_display_name_is_none():
+    mrepo = FakeMembershipRepo(members={(9, "p")})
+    urepo = FakeUserRepo(set())  # user_id 9 no longer exists
+    svc = _svc(prepo=FakePartitionRepo({"p"}), mrepo=mrepo, urepo=urepo)
+    members = await svc.list_members("p")
+    assert members[0]["display_name"] is None
+
+
 @pytest.mark.asyncio
 async def test_add_member_checks_partition_and_user():
     mrepo = FakeMembershipRepo()
diff --git a/ui/src/lib/api/partitions.ts b/ui/src/lib/api/partitions.ts
index 13743a141..99d011842 100644
--- a/ui/src/lib/api/partitions.ts
+++ b/ui/src/lib/api/partitions.ts
@@ -8,7 +8,7 @@ import { request } from "./client";
 //   POST   /partition/{p}                   create (name in path, NO body; caller becomes owner) → 201
 //   PATCH  /partition/{p}                   update config → PartitionDetailResponse
 //   DELETE /partition/{p}                   delete → 204
-//   GET    /partition/{p}/users             members → { members: [{ user_id, role, added_at }] }
+//   GET    /partition/{p}/users             members → { members: [{ user_id, display_name, role, added_at }] }
 //   POST   /partition/{p}/users             add member   (multipart: user_id, role)
 //   PATCH  /partition/{p}/users/{user_id}   change role  (multipart: role)
 //   DELETE /partition/{p}/users/{user_id}   remove member
@@ -194,6 +194,7 @@ export function listPartitionFiles(name: string, limit?: number): Promise<{ file
 
 export interface PartitionMember {
   user_id: number;
+  display_name: string | null;
   role: PartitionRole;
   added_at: string | null;
 }
diff --git a/ui/src/pages/admin/partitions/detail.tsx b/ui/src/pages/admin/partitions/detail.tsx
index 704573d3f..636529aa5 100644
--- a/ui/src/pages/admin/partitions/detail.tsx
+++ b/ui/src/pages/admin/partitions/detail.tsx
@@ -467,7 +467,7 @@ function UsersTab({ partitionName }: { partitionName: string }) {
             <Table>
               <TableHeader>
                 <TableRow>
-                  <TableHead>User ID</TableHead>
+                  <TableHead>User</TableHead>
                   <TableHead>Role</TableHead>
                   <TableHead>Added</TableHead>
                   {canManage && <TableHead>Actions</TableHead>}
@@ -476,8 +476,10 @@ function UsersTab({ partitionName }: { partitionName: string }) {
               <TableBody>
                 {usersQuery.data.members.map((user) => (
                   <TableRow key={user.user_id}>
-                    <TableCell className="font-mono text-sm">
-                      {user.user_id}
+                    <TableCell className="text-sm">
+                      {user.display_name || (
+                        <span className="font-mono text-muted-foreground">{user.user_id}</span>
+                      )}
                     </TableCell>
                     <TableCell>
                       {canManage ? (
@@ -508,7 +510,7 @@ function UsersTab({ partitionName }: { partitionName: string }) {
                       <TableCell>
                         <ConfirmDialog
                           title="Remove User"
-                          description={`Remove user "${user.user_id}" from this partition? They will lose access to partition data.`}
+                          description={`Remove user "${user.display_name || user.user_id}" from this partition? They will lose access to partition data.`}
                           onConfirm={() => removeMutation.mutate(user.user_id)}
                         >
                           <Button