diff --git a/pkg/apis/networking/validation/validation.go b/pkg/apis/networking/validation/validation.go
index cb1d1a6d331..eb08bf23c86 100644
--- a/pkg/apis/networking/validation/validation.go
+++ b/pkg/apis/networking/validation/validation.go
@@ -277,9 +277,9 @@ func ValidateIngressCreate(ingress *networking.Ingress) field.ErrorList {
 	}
 	allErrs = append(allErrs, validateIngress(ingress, opts)...)
 	annotationVal, annotationIsSet := ingress.Annotations[annotationIngressClass]
-	if annotationIsSet && ingress.Spec.IngressClassName != nil {
+	if annotationIsSet && ingress.Spec.IngressClassName != nil && annotationVal != *ingress.Spec.IngressClassName {
 		annotationPath := field.NewPath("annotations").Child(annotationIngressClass)
-		allErrs = append(allErrs, field.Invalid(annotationPath, annotationVal, "can not be set when the class field is also set"))
+		allErrs = append(allErrs, field.Invalid(annotationPath, annotationVal, "must match `ingressClassName` when both are specified"))
 	}
 	return allErrs
 }
diff --git a/pkg/apis/networking/validation/validation_test.go b/pkg/apis/networking/validation/validation_test.go
index b575d486945..65f1a494aff 100644
--- a/pkg/apis/networking/validation/validation_test.go
+++ b/pkg/apis/networking/validation/validation_test.go
@@ -993,12 +993,19 @@ func TestValidateIngressCreate(t *testing.T) {
 			},
 			expectedErrs: field.ErrorList{},
 		},
-		"class field and annotation set": {
+		"class field and annotation set with same value": {
+			tweakIngress: func(ingress *networking.Ingress) {
+				ingress.Spec.IngressClassName = utilpointer.String("foo")
+				ingress.Annotations = map[string]string{annotationIngressClass: "foo"}
+			},
+			expectedErrs: field.ErrorList{},
+		},
+		"class field and annotation set with different value": {
 			tweakIngress: func(ingress *networking.Ingress) {
 				ingress.Spec.IngressClassName = utilpointer.String("bar")
 				ingress.Annotations = map[string]string{annotationIngressClass: "foo"}
 			},
-			expectedErrs: field.ErrorList{field.Invalid(field.NewPath("annotations").Child(annotationIngressClass), "foo", "can not be set when the class field is also set")},
+			expectedErrs: field.ErrorList{field.Invalid(field.NewPath("annotations").Child(annotationIngressClass), "foo", "must match `ingressClassName` when both are specified")},
 		},
 		"valid regex path": {
 			tweakIngress: func(ingress *networking.Ingress) {
diff --git a/pkg/registry/networking/ingress/strategy.go b/pkg/registry/networking/ingress/strategy.go
index fc934d796d1..a23763b9f3d 100644
--- a/pkg/registry/networking/ingress/strategy.go
+++ b/pkg/registry/networking/ingress/strategy.go
@@ -18,6 +18,7 @@ package ingress
 
 import (
 	"context"
+	"fmt"
 
 	apiequality "k8s.io/apimachinery/pkg/api/equality"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -29,6 +30,10 @@ import (
 	"sigs.k8s.io/structured-merge-diff/v4/fieldpath"
 )
 
+const (
+	annotationIngressClass = "kubernetes.io/ingress.class"
+)
+
 // ingressStrategy implements verification logic for Replication Ingress.
 type ingressStrategy struct {
 	runtime.ObjectTyper
@@ -93,7 +98,15 @@ func (ingressStrategy) Validate(ctx context.Context, obj runtime.Object) field.E
 }
 
 // WarningsOnCreate returns warnings for the creation of the given object.
-func (ingressStrategy) WarningsOnCreate(ctx context.Context, obj runtime.Object) []string { return nil }
+func (ingressStrategy) WarningsOnCreate(ctx context.Context, obj runtime.Object) []string {
+	var warnings []string
+	ingress := obj.(*networking.Ingress)
+	_, annotationIsSet := ingress.Annotations[annotationIngressClass]
+	if annotationIsSet && ingress.Spec.IngressClassName == nil {
+		warnings = append(warnings, fmt.Sprintf("annotation %q is deprecated, please use 'spec.ingressClassName' instead", annotationIngressClass))
+	}
+	return warnings
+}
 
 // Canonicalize normalizes the object after validation.
 func (ingressStrategy) Canonicalize(obj runtime.Object) {