diff --git a/api/core/db.py b/api/core/db.py
new file mode 100644
index 000000000000..a97139188f1f
--- /dev/null
+++ b/api/core/db.py
@@ -0,0 +1,5 @@
+from django.contrib.postgres.indexes import GinIndex
+
+
+class UnrestrictedGinIndex(GinIndex):
+    max_name_length = 63
diff --git a/api/environments/identities/migrations/0003_add_idenity_identifier_gin_index.py b/api/environments/identities/migrations/0003_add_idenity_identifier_gin_index.py
new file mode 100644
index 000000000000..f68556da1a17
--- /dev/null
+++ b/api/environments/identities/migrations/0003_add_idenity_identifier_gin_index.py
@@ -0,0 +1,47 @@
+# Generated by Django 4.2.18 on 2025-04-22 10:15
+
+from django.contrib.postgres.operations import TrigramExtension
+from django.db import migrations
+import django.contrib.postgres.indexes
+import django.db.models.functions.text
+
+from core.migration_helpers import PostgresOnlyRunSQL
+import core.db
+
+
+_create_index_sql = "CREATE INDEX CONCURRENTLY IF NOT EXISTS environments_identity_identifier_gin_idx ON environments_identity USING GIN (UPPER(identifier) gin_trgm_ops);"
+_create_index_reverse_sql = (
+    "DROP INDEX CONCURRENTLY IF EXISTS environments_identity_identifier_gin_idx;"
+)
+
+
+class Migration(migrations.Migration):
+    atomic = False
+
+    dependencies = [
+        ("identities", "0002_alter_identity_index_together"),
+    ]
+
+    operations = [
+        migrations.SeparateDatabaseAndState(
+            state_operations=[
+                migrations.AddIndex(
+                    model_name="identity",
+                    index=core.db.UnrestrictedGinIndex(
+                        django.contrib.postgres.indexes.OpClass(
+                            django.db.models.functions.text.Upper("identifier"),
+                            name="gin_trgm_ops",
+                        ),
+                        name="environments_identity_identifier_gin_idx",
+                    ),
+                ),
+            ],
+            database_operations=[
+                TrigramExtension(),
+                PostgresOnlyRunSQL(
+                    sql=_create_index_sql,
+                    reverse_sql=_create_index_reverse_sql,
+                ),
+            ],
+        ),
+    ]
diff --git a/api/environments/identities/models.py b/api/environments/identities/models.py
index 9003fd65f3b0..9c812c141e32 100644
--- a/api/environments/identities/models.py
+++ b/api/environments/identities/models.py
@@ -1,11 +1,14 @@
 import typing
 from itertools import chain
 
+from django.contrib.postgres.indexes import OpClass
 from django.db import models
 from django.db.models import Prefetch, Q
+from django.db.models.functions import Upper
 from django.utils import timezone
 from flag_engine.segments.evaluator import evaluate_identity_in_segment
 
+from core.db import UnrestrictedGinIndex
 from environments.identities.managers import IdentityManager
 from environments.identities.traits.models import Trait
 from environments.models import Environment
@@ -40,6 +43,12 @@ class Meta:
         # avoid any downtime. If people using MySQL / Oracle have issues with poor performance on the identities table,
         # we can provide them the SQL to add it manually in a small window of downtime.
         index_together = (("environment", "created_date"),)
+        indexes = [
+            UnrestrictedGinIndex(
+                OpClass(Upper("identifier"), name="gin_trgm_ops"),
+                name="environments_identity_identifier_gin_idx",
+            ),
+        ]
 
     def natural_key(self):  # type: ignore[no-untyped-def]
         return self.identifier, self.environment.api_key