diff --git a/conformance/tests/httproute-request-mirror-backend.yaml b/conformance/tests/httproute-request-mirror-backend.yaml
new file mode 100644
index 0000000000..5ab311a640
--- /dev/null
+++ b/conformance/tests/httproute-request-mirror-backend.yaml
@@ -0,0 +1,20 @@
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: request-mirror
+  namespace: gateway-conformance-infra
+spec:
+  parentRefs:
+  - name: same-namespace
+  rules:
+  - backendRefs:
+    - name: infra-backend-v1
+      namespace: gateway-conformance-infra
+      port: 8080
+      filters:
+      - type: RequestMirror
+        requestMirror:
+          backendRef:
+            name: infra-backend-v2
+            namespace: gateway-conformance-infra
+            port: 8080
diff --git a/conformance/tests/httproute-request-mirror.go b/conformance/tests/httproute-request-mirror.go
index fa4c36b44b..bdd6eaad93 100644
--- a/conformance/tests/httproute-request-mirror.go
+++ b/conformance/tests/httproute-request-mirror.go
@@ -28,7 +28,24 @@ import (
 )
 
 func init() {
-	ConformanceTests = append(ConformanceTests, HTTPRouteRequestMirror)
+	ConformanceTests = append(ConformanceTests,
+		HTTPRouteRequestMirror,
+		HTTPRouteBackendRequestMirror,
+	)
+}
+
+var HTTPRouteBackendRequestMirror = suite.ConformanceTest{
+	ShortName:   "HTTPRouteBackendRequestMirror",
+	Description: "An HTTPRoute backendRef with request mirror filter",
+	Manifests:   []string{"tests/httproute-request-mirror-backend.yaml"},
+	Features: []features.SupportedFeature{
+		features.SupportGateway,
+		features.SupportHTTPRoute,
+		features.SupportHTTPRouteBackendRequestMirror,
+	},
+	Test: func(t *testing.T, suite *suite.ConformanceTestSuite) {
+		RunHTTPRouteRequestMirrorTest(t, suite, HTTPRouteRequestMirrorTestCases)
+	},
 }
 
 var HTTPRouteRequestMirror = suite.ConformanceTest{
@@ -41,64 +58,69 @@ var HTTPRouteRequestMirror = suite.ConformanceTest{
 		features.SupportHTTPRouteRequestMirror,
 	},
 	Test: func(t *testing.T, suite *suite.ConformanceTestSuite) {
-		ns := "gateway-conformance-infra"
-		routeNN := types.NamespacedName{Name: "request-mirror", Namespace: ns}
-		gwNN := types.NamespacedName{Name: "same-namespace", Namespace: ns}
-		gwAddr := kubernetes.GatewayAndHTTPRoutesMustBeAccepted(t, suite.Client, suite.TimeoutConfig, suite.ControllerName, kubernetes.NewGatewayRef(gwNN), routeNN)
+		RunHTTPRouteRequestMirrorTest(t, suite, HTTPRouteRequestMirrorTestCases)
+		RunHTTPRouteRequestMirrorTest(t, suite, HTTPRouteRequestMirrorAndModifyRequestHeaderTestCases)
+	},
+}
 
-		testCases := []http.ExpectedResponse{
-			{
-				Request: http.Request{
-					Path: "/mirror",
-				},
-				ExpectedRequest: &http.ExpectedRequest{
-					Request: http.Request{
-						Path: "/mirror",
-					},
-				},
-				Backend: "infra-backend-v1",
-				MirroredTo: []http.BackendRef{{
-					Name:      "infra-backend-v2",
-					Namespace: ns,
-				}},
-				Namespace: ns,
-			},
-			{
-				Request: http.Request{
-					Path: "/mirror-and-modify-headers",
-					Headers: map[string]string{
-						"X-Header-Remove":     "remove-val",
-						"X-Header-Add-Append": "append-val-1",
-					},
-				},
-				ExpectedRequest: &http.ExpectedRequest{
-					Request: http.Request{
-						Path: "/mirror-and-modify-headers",
-						Headers: map[string]string{
-							"X-Header-Add":        "header-val-1",
-							"X-Header-Add-Append": "append-val-1,header-val-2",
-							"X-Header-Set":        "set-overwrites-values",
-						},
-					},
-					AbsentHeaders: []string{"X-Header-Remove"},
-				},
-				Namespace: ns,
-				Backend:   "infra-backend-v1",
-				MirroredTo: []http.BackendRef{{
-					Name:      "infra-backend-v2",
-					Namespace: ns,
-				}},
+func RunHTTPRouteRequestMirrorTest(t *testing.T, suite *suite.ConformanceTestSuite, testCases []http.ExpectedResponse) {
+	ns := "gateway-conformance-infra"
+	routeNN := types.NamespacedName{Name: "request-mirror", Namespace: ns}
+	gwNN := types.NamespacedName{Name: "same-namespace", Namespace: ns}
+	gwAddr := kubernetes.GatewayAndHTTPRoutesMustBeAccepted(t, suite.Client, suite.TimeoutConfig, suite.ControllerName, kubernetes.NewGatewayRef(gwNN), routeNN)
+
+	for i := range testCases {
+		// Declare tc here to avoid loop variable
+		// reuse issues across parallel tests.
+		tc := testCases[i]
+		t.Run(tc.GetTestCaseName(i), func(t *testing.T) {
+			t.Parallel()
+			http.MakeRequestAndExpectEventuallyConsistentResponse(t, suite.RoundTripper, suite.TimeoutConfig, gwAddr, tc)
+			http.ExpectMirroredRequest(t, suite.Client, suite.Clientset, tc.MirroredTo, tc.Request.Path)
+		})
+	}
+}
+
+var HTTPRouteRequestMirrorTestCases = []http.ExpectedResponse{{
+	Request: http.Request{
+		Path: "/mirror",
+	},
+	ExpectedRequest: &http.ExpectedRequest{
+		Request: http.Request{
+			Path: "/mirror",
+		},
+	},
+	Backend: "infra-backend-v1",
+	MirroredTo: []http.BackendRef{{
+		Name:      "infra-backend-v2",
+		Namespace: "gateway-conformance-infra",
+	}},
+	Namespace: "gateway-conformance-infra",
+}}
+
+var HTTPRouteRequestMirrorAndModifyRequestHeaderTestCases = []http.ExpectedResponse{{
+	Request: http.Request{
+		Path: "/mirror-and-modify-headers",
+		Headers: map[string]string{
+			"X-Header-Remove":     "remove-val",
+			"X-Header-Add-Append": "append-val-1",
+		},
+	},
+	ExpectedRequest: &http.ExpectedRequest{
+		Request: http.Request{
+			Path: "/mirror-and-modify-headers",
+			Headers: map[string]string{
+				"X-Header-Add":        "header-val-1",
+				"X-Header-Add-Append": "append-val-1,header-val-2",
+				"X-Header-Set":        "set-overwrites-values",
 			},
-		}
-		for i := range testCases {
-			// Declare tc here to avoid loop variable
-			// reuse issues across parallel tests.
-			tc := testCases[i]
-			t.Run(tc.GetTestCaseName(i), func(t *testing.T) {
-				t.Parallel()
-				http.MakeRequestAndExpectEventuallyConsistentResponse(t, suite.RoundTripper, suite.TimeoutConfig, gwAddr, tc)
-				http.ExpectMirroredRequest(t, suite.Client, suite.Clientset, tc.MirroredTo, tc.Request.Path)
-			})
-		}
+		},
+		AbsentHeaders: []string{"X-Header-Remove"},
 	},
-}
+	Namespace: "gateway-conformance-infra",
+	Backend:   "infra-backend-v1",
+	MirroredTo: []http.BackendRef{{
+		Name:      "infra-backend-v2",
+		Namespace: "gateway-conformance-infra",
+	}},
+}}
diff --git a/pkg/features/features.go b/pkg/features/features.go
index fcb6d28019..aa26fae374 100644
--- a/pkg/features/features.go
+++ b/pkg/features/features.go
@@ -128,6 +128,9 @@ const (
 	// This option indicates support for HTTPRoute request mirror (extended conformance).
 	SupportHTTPRouteRequestMirror SupportedFeature = "HTTPRouteRequestMirror"
 
+	// This option indicates support for HTTPRoute backend request mirror (extended conformance).
+	SupportHTTPRouteBackendRequestMirror SupportedFeature = "HTTPRouteBackendRequestMirror"
+
 	// This option indicates support for multiple RequestMirror filters within the same HTTPRoute rule (extended conformance).
 	SupportHTTPRouteRequestMultipleMirrors SupportedFeature = "HTTPRouteRequestMultipleMirrors"
 
@@ -154,6 +157,7 @@ var HTTPRouteExtendedFeatures = sets.New(
 	SupportHTTPRouteHostRewrite,
 	SupportHTTPRoutePathRewrite,
 	SupportHTTPRouteRequestMirror,
+	SupportHTTPRouteBackendRequestMirror,
 	SupportHTTPRouteRequestMultipleMirrors,
 	SupportHTTPRouteRequestTimeout,
 	SupportHTTPRouteBackendTimeout,