diff --git a/internal/envconfig/xds.go b/internal/envconfig/xds.go
index 55aaeea8b455..af09711a3e88 100644
--- a/internal/envconfig/xds.go
+++ b/internal/envconfig/xds.go
@@ -84,9 +84,9 @@ var (
 	// "GRPC_XDS_EXPERIMENTAL_RBAC" to "false".
 	XDSRBAC = !strings.EqualFold(os.Getenv(rbacSupportEnv), "false")
 	// XDSOutlierDetection indicates whether outlier detection support is
-	// enabled, which can be enabled by setting the environment variable
-	// "GRPC_EXPERIMENTAL_ENABLE_OUTLIER_DETECTION" to "true".
-	XDSOutlierDetection = strings.EqualFold(os.Getenv(outlierDetectionSupportEnv), "true")
+	// enabled, which can be disabled by setting the environment variable
+	// "GRPC_EXPERIMENTAL_ENABLE_OUTLIER_DETECTION" to "false".
+	XDSOutlierDetection = !strings.EqualFold(os.Getenv(outlierDetectionSupportEnv), "false")
 	// XDSFederation indicates whether federation support is enabled.
 	XDSFederation = strings.EqualFold(os.Getenv(federationEnv), "true")
 
diff --git a/test/xds/xds_client_outlier_detection_test.go b/test/xds/xds_client_outlier_detection_test.go
index b53439cf66ce..b9868876e42a 100644
--- a/test/xds/xds_client_outlier_detection_test.go
+++ b/test/xds/xds_client_outlier_detection_test.go
@@ -33,7 +33,6 @@ import (
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials/insecure"
 	"google.golang.org/grpc/internal"
-	"google.golang.org/grpc/internal/envconfig"
 	"google.golang.org/grpc/internal/stubserver"
 	"google.golang.org/grpc/internal/testutils/xds/e2e"
 	testgrpc "google.golang.org/grpc/test/grpc_testing"
@@ -49,13 +48,8 @@ import (
 // Detection balancer. This test verifies that an RPC is able to proceed
 // normally with this configuration.
 func (s) TestOutlierDetection_NoopConfig(t *testing.T) {
-	oldOD := envconfig.XDSOutlierDetection
-	envconfig.XDSOutlierDetection = true
 	internal.RegisterOutlierDetectionBalancerForTesting()
-	defer func() {
-		envconfig.XDSOutlierDetection = oldOD
-		internal.UnregisterOutlierDetectionBalancerForTesting()
-	}()
+	defer internal.UnregisterOutlierDetectionBalancerForTesting()
 
 	managementServer, nodeID, _, resolver, cleanup1 := e2e.SetupManagementServer(t, nil)
 	defer cleanup1()
@@ -129,13 +123,8 @@ func clusterWithOutlierDetection(clusterName, edsServiceName string, secLevel e2
 // Detection Balancer should eject the connection to the backend which
 // constantly errors, and thus RPC's should mainly go to backend 1 and 2.
 func (s) TestOutlierDetectionWithOutlier(t *testing.T) {
-	oldOD := envconfig.XDSOutlierDetection
-	envconfig.XDSOutlierDetection = true
 	internal.RegisterOutlierDetectionBalancerForTesting()
-	defer func() {
-		envconfig.XDSOutlierDetection = oldOD
-		internal.UnregisterOutlierDetectionBalancerForTesting()
-	}()
+	defer internal.UnregisterOutlierDetectionBalancerForTesting()
 
 	managementServer, nodeID, _, resolver, cleanup := e2e.SetupManagementServer(t, nil)
 	defer cleanup()
diff --git a/xds/internal/balancer/cdsbalancer/cdsbalancer_test.go b/xds/internal/balancer/cdsbalancer/cdsbalancer_test.go
index dfa47913ae29..18d20e28f246 100644
--- a/xds/internal/balancer/cdsbalancer/cdsbalancer_test.go
+++ b/xds/internal/balancer/cdsbalancer/cdsbalancer_test.go
@@ -29,7 +29,6 @@ import (
 	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/internal"
-	"google.golang.org/grpc/internal/envconfig"
 	"google.golang.org/grpc/internal/grpctest"
 	internalserviceconfig "google.golang.org/grpc/internal/serviceconfig"
 	"google.golang.org/grpc/internal/testutils"
@@ -366,14 +365,11 @@ func (s) TestUpdateClientConnStateWithSameState(t *testing.T) {
 // different updates and verifies that the expect ClientConnState is propagated
 // to the edsBalancer.
 func (s) TestHandleClusterUpdate(t *testing.T) {
-	oldOutlierDetection := envconfig.XDSOutlierDetection
-	envconfig.XDSOutlierDetection = true
 	xdsC, cdsB, edsB, _, cancel := setupWithWatch(t)
 	xdsC.SetBootstrapConfig(&bootstrap.Config{
 		XDSServer: defaultTestAuthorityServerConfig,
 	})
 	defer func() {
-		envconfig.XDSOutlierDetection = oldOutlierDetection
 		cancel()
 		cdsB.Close()
 	}()
diff --git a/xds/internal/balancer/clusterresolver/clusterresolver_test.go b/xds/internal/balancer/clusterresolver/clusterresolver_test.go
index f6f6249d9e89..db3ab78f1232 100644
--- a/xds/internal/balancer/clusterresolver/clusterresolver_test.go
+++ b/xds/internal/balancer/clusterresolver/clusterresolver_test.go
@@ -31,7 +31,6 @@ import (
 	"google.golang.org/grpc/balancer/weightedtarget"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/internal"
-	"google.golang.org/grpc/internal/envconfig"
 	"google.golang.org/grpc/internal/grpctest"
 	internalserviceconfig "google.golang.org/grpc/internal/serviceconfig"
 	"google.golang.org/grpc/internal/testutils"
@@ -533,12 +532,7 @@ func newLBConfigWithOneEDSAndOutlierDetection(edsServiceName string, odCfg outli
 // Configuration sent downward should have a top level Outlier Detection Policy
 // for each priority.
 func (s) TestOutlierDetection(t *testing.T) {
-	oldOutlierDetection := envconfig.XDSOutlierDetection
-	envconfig.XDSOutlierDetection = true
 	internal.RegisterOutlierDetectionBalancerForTesting()
-	defer func() {
-		envconfig.XDSOutlierDetection = oldOutlierDetection
-	}()
 
 	edsLBCh := testutils.NewChannel()
 	xdsC, cleanup := setup(edsLBCh)
diff --git a/xds/internal/balancer/clusterresolver/configbuilder_test.go b/xds/internal/balancer/clusterresolver/configbuilder_test.go
index d050df11b02a..b53514bef86c 100644
--- a/xds/internal/balancer/clusterresolver/configbuilder_test.go
+++ b/xds/internal/balancer/clusterresolver/configbuilder_test.go
@@ -31,7 +31,6 @@ import (
 	"google.golang.org/grpc/balancer/roundrobin"
 	"google.golang.org/grpc/balancer/weightedroundrobin"
 	"google.golang.org/grpc/balancer/weightedtarget"
-	"google.golang.org/grpc/internal/envconfig"
 	"google.golang.org/grpc/internal/hierarchy"
 	internalserviceconfig "google.golang.org/grpc/internal/serviceconfig"
 	"google.golang.org/grpc/resolver"
@@ -323,12 +322,6 @@ func TestBuildPriorityConfig(t *testing.T) {
 // priority should be an Outlier Detection balancer, with a Cluster Impl
 // Balancer as a child.
 func TestBuildPriorityConfigWithOutlierDetection(t *testing.T) {
-	oldOutlierDetection := envconfig.XDSOutlierDetection
-	envconfig.XDSOutlierDetection = true
-	defer func() {
-		envconfig.XDSOutlierDetection = oldOutlierDetection
-	}()
-
 	gotConfig, _, _ := buildPriorityConfig([]priorityConfig{
 		{
 			// EDS - OD config should be the top level for both of the EDS
diff --git a/xds/internal/xdsclient/xdsresource/unmarshal_cds_test.go b/xds/internal/xdsclient/xdsresource/unmarshal_cds_test.go
index 67e057a6c400..fa8f4d4bbcc8 100644
--- a/xds/internal/xdsclient/xdsresource/unmarshal_cds_test.go
+++ b/xds/internal/xdsclient/xdsresource/unmarshal_cds_test.go
@@ -1690,9 +1690,6 @@ func (s) TestUnmarshalCluster(t *testing.T) {
 }
 
 func (s) TestValidateClusterWithOutlierDetection(t *testing.T) {
-	oldOutlierDetectionSupportEnv := envconfig.XDSOutlierDetection
-	envconfig.XDSOutlierDetection = true
-	defer func() { envconfig.XDSOutlierDetection = oldOutlierDetectionSupportEnv }()
 	odToClusterProto := func(od *v3clusterpb.OutlierDetection) *v3clusterpb.Cluster {
 		// Cluster parsing doesn't fail with respect to fields orthogonal to
 		// outlier detection.