diff --git a/api/segment_membership/services.py b/api/segment_membership/services.py
index 16e97da5ece2..9565ca2ab5e2 100644
--- a/api/segment_membership/services.py
+++ b/api/segment_membership/services.py
@@ -160,11 +160,13 @@ def get_segment_members_page(
     *,
     cursor: str | None,
     limit: int,
+    q: str | None = None,
 ) -> list[SegmentMember]:
     """Return one page of identities matching `segment` in `environment`,
     ordered by `identifier`.
 
     Provide identifier as `cursor` to get a page after that identifier.
+    Provide `q` to filter to identifiers containing it (case-insensitive).
     """
     translate_ctx = TranslateContext(
         evaluation_context=EvaluationContext(
@@ -189,6 +191,9 @@ def get_segment_members_page(
     if cursor:
         conditions.append("i.identifier > %(cursor)s")
         params["cursor"] = cursor
+    if q:
+        conditions.append("positionCaseInsensitiveUTF8(i.identifier, %(q)s) > 0")
+        params["q"] = q
     conditions.append(f"({predicate})")
 
     sql = (
diff --git a/api/segments/serializers.py b/api/segments/serializers.py
index e8d116db9473..7bb06eaa0f85 100644
--- a/api/segments/serializers.py
+++ b/api/segments/serializers.py
@@ -257,6 +257,10 @@ class SegmentMembersQuerySerializer(serializers.Serializer):  # type: ignore[typ
         required=False,
         help_text="The identifier of the previous page's last row; omit for the first page.",
     )
+    q = serializers.CharField(
+        required=False,
+        help_text="Case-insensitive substring to filter members by identifier.",
+    )
     limit = serializers.IntegerField(
         required=False,
         default=100,
diff --git a/api/segments/views.py b/api/segments/views.py
index b93efa083012..b1dbafa4ed33 100644
--- a/api/segments/views.py
+++ b/api/segments/views.py
@@ -178,8 +178,15 @@ def associated_features(self, request, *args, **kwargs):  # type: ignore[no-unty
     @action(detail=True, methods=["GET"], url_path="members")
     def members(self, request: Request, *args: Any, **kwargs: Any) -> Response:
         user: "FFAdminUser" = request.user  # type: ignore[assignment]
-        segment = self.get_object()
-        project = segment.project
+        project = self.get_project()
+        # Fetch by pk directly rather than via get_object()/get_queryset(): the
+        # latter applies the list endpoint's `q` (segment-name search), which
+        # would filter this segment out when `q` is used here to search members.
+        segment = get_object_or_404(
+            Segment.live_objects.filter(project=project, is_system_segment=False),
+            pk=self.kwargs["pk"],
+        )
+        self.check_object_permissions(request, segment)
         if not is_membership_enabled(project.organisation):
             raise NotFound()
 
@@ -194,11 +201,12 @@ def members(self, request: Request, *args: Any, **kwargs: Any) -> Response:
 
         limit = query_serializer.validated_data["limit"]
         cursor = query_serializer.validated_data.get("cursor")
+        q = query_serializer.validated_data.get("q")
         with flagsmith_segment_membership_read_duration_seconds.time():
             # Fetch one extra row to detect whether a further page exists, so the
             # last page doesn't advertise a phantom (empty) next page.
             members = get_segment_members_page(
-                segment, environment, cursor=cursor, limit=limit + 1
+                segment, environment, cursor=cursor, limit=limit + 1, q=q
             )
 
         has_more = len(members) > limit
diff --git a/api/tests/integration/segment_membership/test_segment_members_endpoint.py b/api/tests/integration/segment_membership/test_segment_members_endpoint.py
index 32ff601f09e8..61d205710a10 100644
--- a/api/tests/integration/segment_membership/test_segment_members_endpoint.py
+++ b/api/tests/integration/segment_membership/test_segment_members_endpoint.py
@@ -138,6 +138,37 @@ def test_get_segment_members__matching_identities__returns_members(
     }
 
 
+@pytest.mark.clickhouse
+def test_get_segment_members__q__filters_by_identifier(
+    segment_membership_identities: None,
+    admin_client: APIClient,
+    project: int,
+    environment: int,
+    segment: int,
+    enable_features: EnableFeaturesFixture,
+) -> None:
+    # Given
+    enable_features("segment_membership_inspection")
+
+    # When
+    response = admin_client.get(
+        f"/api/v1/projects/{project}/segments/{segment}/members/?environment={environment}&q=ali"
+    )
+
+    # Then
+    assert response.status_code == status.HTTP_200_OK
+    assert response.json() == {
+        "results": [
+            {
+                "identifier": "alice",
+                "identity_key": "alice_key",
+                "traits": {"foo": "bar"},
+            },
+        ],
+        "next_cursor": None,
+    }
+
+
 @pytest.mark.clickhouse
 def test_get_segment_members__more_results_than_limit__returns_next_cursor(
     segment_membership_identities: None,
diff --git a/api/tests/unit/segment_membership/test_unit_segment_membership_services.py b/api/tests/unit/segment_membership/test_unit_segment_membership_services.py
index 2f612bac038f..042a3d117aa7 100644
--- a/api/tests/unit/segment_membership/test_unit_segment_membership_services.py
+++ b/api/tests/unit/segment_membership/test_unit_segment_membership_services.py
@@ -254,6 +254,80 @@ def test_get_segment_members_page__limit__caps_results(
     ]
 
 
+@pytest.mark.parametrize(
+    "q,expected_result",
+    [
+        pytest.param(
+            "ali",
+            [
+                SegmentMember(
+                    identifier="alice",
+                    identity_key="alice_key",
+                    traits={"foo": "bar"},
+                ),
+            ],
+            id="substring",
+        ),
+        pytest.param(
+            "ALICE",
+            [
+                SegmentMember(
+                    identifier="alice",
+                    identity_key="alice_key",
+                    traits={"foo": "bar"},
+                ),
+            ],
+            id="case-insensitive",
+        ),
+        pytest.param("zzz", [], id="no-match"),
+    ],
+)
+@pytest.mark.clickhouse
+def test_get_segment_members_page__q__returns_expected(
+    segment_membership_identities: None,
+    matching_segment: Segment,
+    environment: Environment,
+    q: str,
+    expected_result: list[SegmentMember],
+) -> None:
+    # Given / When
+    members = get_segment_members_page(
+        matching_segment,
+        environment,
+        cursor=None,
+        limit=100,
+        q=q,
+    )
+
+    # Then
+    assert members == expected_result
+
+
+@pytest.mark.clickhouse
+def test_get_segment_members_page__q_matches_beyond_first_page__still_found(
+    segment_membership_identities: None,
+    matching_segment: Segment,
+    environment: Environment,
+) -> None:
+    # Given / When
+    members = get_segment_members_page(
+        matching_segment,
+        environment,
+        cursor=None,
+        limit=1,
+        q="bob",
+    )
+
+    # Then
+    assert members == [
+        SegmentMember(
+            identifier="bob",
+            identity_key="bob_key",
+            traits={"foo": "bar"},
+        ),
+    ]
+
+
 def test_enqueue_membership_refresh__flag_on__enqueues_refresh(
     run_tasks: RunTasksFixture,
     mocker: MockerFixture,
diff --git a/docs/docs/deployment-self-hosting/observability/_events-catalogue.md b/docs/docs/deployment-self-hosting/observability/_events-catalogue.md
index f9d84605dc07..5c049694e96a 100644
--- a/docs/docs/deployment-self-hosting/observability/_events-catalogue.md
+++ b/docs/docs/deployment-self-hosting/observability/_events-catalogue.md
@@ -397,7 +397,7 @@ Attributes:
 ### `segment_membership.members.segment.skipped`
 
 Logged at `error` from:
- - `api/segment_membership/services.py:180`
+ - `api/segment_membership/services.py:182`
 
 Attributes:
  - `reason`