diff --git a/coderd/database/dump.sql b/coderd/database/dump.sql
index daa55fb1bb..5b23e7b288 100644
--- a/coderd/database/dump.sql
+++ b/coderd/database/dump.sql
@@ -3345,6 +3345,10 @@ CREATE INDEX tasks_organization_id_idx ON tasks USING btree (organization_id);
 
 CREATE INDEX tasks_owner_id_idx ON tasks USING btree (owner_id);
 
+CREATE UNIQUE INDEX tasks_owner_id_name_unique_idx ON tasks USING btree (owner_id, lower(name)) WHERE (deleted_at IS NULL);
+
+COMMENT ON INDEX tasks_owner_id_name_unique_idx IS 'Index to ensure uniqueness for task owner/name';
+
 CREATE INDEX tasks_workspace_id_idx ON tasks USING btree (workspace_id);
 
 CREATE INDEX template_usage_stats_start_time_idx ON template_usage_stats USING btree (start_time DESC);
diff --git a/coderd/database/migrations/000380_task_name_unique.down.sql b/coderd/database/migrations/000380_task_name_unique.down.sql
new file mode 100644
index 0000000000..b15f332555
--- /dev/null
+++ b/coderd/database/migrations/000380_task_name_unique.down.sql
@@ -0,0 +1 @@
+DROP INDEX IF EXISTS tasks_owner_id_name_unique_idx;
diff --git a/coderd/database/migrations/000380_task_name_unique.up.sql b/coderd/database/migrations/000380_task_name_unique.up.sql
new file mode 100644
index 0000000000..13ccf0b2d3
--- /dev/null
+++ b/coderd/database/migrations/000380_task_name_unique.up.sql
@@ -0,0 +1,2 @@
+CREATE UNIQUE INDEX IF NOT EXISTS tasks_owner_id_name_unique_idx ON tasks (owner_id, LOWER(name)) WHERE deleted_at IS NULL;
+COMMENT ON INDEX tasks_owner_id_name_unique_idx IS 'Index to ensure uniqueness for task owner/name';
diff --git a/coderd/database/querier_test.go b/coderd/database/querier_test.go
index 1409a079f5..01584a03ba 100644
--- a/coderd/database/querier_test.go
+++ b/coderd/database/querier_test.go
@@ -7105,6 +7105,88 @@ func TestGetTaskByWorkspaceID(t *testing.T) {
 	}
 }
 
+func TestTaskNameUniqueness(t *testing.T) {
+	t.Parallel()
+
+	db, _ := dbtestutil.NewDB(t)
+
+	org := dbgen.Organization(t, db, database.Organization{})
+	user1 := dbgen.User(t, db, database.User{})
+	user2 := dbgen.User(t, db, database.User{})
+	template := dbgen.Template(t, db, database.Template{
+		OrganizationID: org.ID,
+		CreatedBy:      user1.ID,
+	})
+	tv := dbgen.TemplateVersion(t, db, database.TemplateVersion{
+		TemplateID:     uuid.NullUUID{UUID: template.ID, Valid: true},
+		OrganizationID: org.ID,
+		CreatedBy:      user1.ID,
+	})
+
+	taskName := "my-task"
+
+	// Create initial task for user1.
+	task1 := dbgen.Task(t, db, database.TaskTable{
+		OrganizationID:    org.ID,
+		OwnerID:           user1.ID,
+		Name:              taskName,
+		TemplateVersionID: tv.ID,
+		Prompt:            "Test prompt",
+	})
+	require.NotEqual(t, uuid.Nil, task1.ID)
+
+	tests := []struct {
+		name     string
+		ownerID  uuid.UUID
+		taskName string
+		wantErr  bool
+	}{
+		{
+			name:     "duplicate task name same user",
+			ownerID:  user1.ID,
+			taskName: taskName,
+			wantErr:  true,
+		},
+		{
+			name:     "duplicate task name different case same user",
+			ownerID:  user1.ID,
+			taskName: "MY-TASK",
+			wantErr:  true,
+		},
+		{
+			name:     "same task name different user",
+			ownerID:  user2.ID,
+			taskName: taskName,
+			wantErr:  false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			ctx := testutil.Context(t, testutil.WaitShort)
+
+			task, err := db.InsertTask(ctx, database.InsertTaskParams{
+				OrganizationID:     org.ID,
+				OwnerID:            tt.ownerID,
+				Name:               tt.taskName,
+				TemplateVersionID:  tv.ID,
+				TemplateParameters: json.RawMessage("{}"),
+				Prompt:             "Test prompt",
+				CreatedAt:          dbtime.Now(),
+			})
+			if tt.wantErr {
+				require.Error(t, err)
+			} else {
+				require.NoError(t, err)
+				require.NotEqual(t, uuid.Nil, task.ID)
+				require.NotEqual(t, task1.ID, task.ID)
+			}
+		})
+	}
+}
+
 func TestUsageEventsTrigger(t *testing.T) {
 	t.Parallel()
 
diff --git a/coderd/database/unique_constraint.go b/coderd/database/unique_constraint.go
index 58206e8ad2..03e2efa093 100644
--- a/coderd/database/unique_constraint.go
+++ b/coderd/database/unique_constraint.go
@@ -121,6 +121,7 @@ const (
 	UniqueNotificationMessagesDedupeHashIndex                 UniqueConstraint = "notification_messages_dedupe_hash_idx"                           // CREATE UNIQUE INDEX notification_messages_dedupe_hash_idx ON notification_messages USING btree (dedupe_hash);
 	UniqueOrganizationsSingleDefaultOrg                       UniqueConstraint = "organizations_single_default_org"                                // CREATE UNIQUE INDEX organizations_single_default_org ON organizations USING btree (is_default) WHERE (is_default = true);
 	UniqueProvisionerKeysOrganizationIDNameIndex              UniqueConstraint = "provisioner_keys_organization_id_name_idx"                       // CREATE UNIQUE INDEX provisioner_keys_organization_id_name_idx ON provisioner_keys USING btree (organization_id, lower((name)::text));
+	UniqueTasksOwnerIDNameUniqueIndex                         UniqueConstraint = "tasks_owner_id_name_unique_idx"                                  // CREATE UNIQUE INDEX tasks_owner_id_name_unique_idx ON tasks USING btree (owner_id, lower(name)) WHERE (deleted_at IS NULL);
 	UniqueTemplateUsageStatsStartTimeTemplateIDUserIDIndex    UniqueConstraint = "template_usage_stats_start_time_template_id_user_id_idx"         // CREATE UNIQUE INDEX template_usage_stats_start_time_template_id_user_id_idx ON template_usage_stats USING btree (start_time, template_id, user_id);
 	UniqueTemplatesOrganizationIDNameIndex                    UniqueConstraint = "templates_organization_id_name_idx"                              // CREATE UNIQUE INDEX templates_organization_id_name_idx ON templates USING btree (organization_id, lower((name)::text)) WHERE (deleted = false);
 	UniqueUserLinksLinkedIDLoginTypeIndex                     UniqueConstraint = "user_links_linked_id_login_type_idx"                             // CREATE UNIQUE INDEX user_links_linked_id_login_type_idx ON user_links USING btree (linked_id, login_type) WHERE (linked_id <> ''::text);