diff --git a/xds/internal/balancer/ringhash/config.go b/xds/internal/balancer/ringhash/config.go
index eaa6ca233d45..044d698a27bc 100644
--- a/xds/internal/balancer/ringhash/config.go
+++ b/xds/internal/balancer/ringhash/config.go
@@ -73,6 +73,7 @@ func parseConfig(c json.RawMessage) (*LBConfig, error) {
 		cfg.RequestHashHeader = ""
 	}
 	if cfg.RequestHashHeader != "" {
+		cfg.RequestHashHeader = strings.ToLower(cfg.RequestHashHeader)
 		// See rules in https://github.com/grpc/proposal/blob/master/A76-ring-hash-improvements.md#explicitly-setting-the-request-hash-key
 		if err := metadata.ValidateKey(cfg.RequestHashHeader); err != nil {
 			return nil, fmt.Errorf("invalid requestHashHeader %q: %v", cfg.RequestHashHeader, err)
diff --git a/xds/internal/balancer/ringhash/config_test.go b/xds/internal/balancer/ringhash/config_test.go
index 9588a8984c6e..b3772e4574d7 100644
--- a/xds/internal/balancer/ringhash/config_test.go
+++ b/xds/internal/balancer/ringhash/config_test.go
@@ -118,6 +118,16 @@ func (s) TestParseConfig(t *testing.T) {
 				RequestHashHeader: "x-foo",
 			},
 		},
+		{
+			name:                "request metadata key set with uppercase letters",
+			js:                  `{"requestHashHeader": "x-FOO"}`,
+			requestHeaderEnvVar: true,
+			want: &LBConfig{
+				MinRingSize:       defaultMinSize,
+				MaxRingSize:       defaultMaxSize,
+				RequestHashHeader: "x-foo",
+			},
+		},
 		{
 			name:                "invalid request hash header",
 			js:                  `{"requestHashHeader": "!invalid"}`,