diff --git a/.changelog/4722.txt b/.changelog/4722.txt
new file mode 100644
index 0000000000..58db78a038
--- /dev/null
+++ b/.changelog/4722.txt
@@ -0,0 +1,3 @@
+```release-note:bug
+serviceusage: Made `google_project_service.service` validation reject invalid service domains that don't contain a period
+```
diff --git a/google-beta/resource_google_project_service.go b/google-beta/resource_google_project_service.go
index b627b61679..e89a6f4c1f 100644
--- a/google-beta/resource_google_project_service.go
+++ b/google-beta/resource_google_project_service.go
@@ -56,6 +56,21 @@ var renamedServicesByOldAndNewServiceNames = mergeStringMaps(renamedServices, re
 
 const maxServiceUsageBatchSize = 20
 
+func validateProjectServiceService(val interface{}, key string) (warns []string, errs []error) {
+	bannedServicesFunc := StringNotInSlice(append(ignoredProjectServices, bannedProjectServices...), false)
+	warns, errs = bannedServicesFunc(val, key)
+	if len(errs) > 0 {
+		return
+	}
+
+	// StringNotInSlice already validates that this is a string
+	v, _ := val.(string)
+	if !strings.Contains(v, ".") {
+		errs = append(errs, fmt.Errorf("expected %s to be a domain like serviceusage.googleapis.com", v))
+	}
+	return
+}
+
 func resourceGoogleProjectService() *schema.Resource {
 	return &schema.Resource{
 		Create: resourceGoogleProjectServiceCreate,
@@ -79,7 +94,7 @@ func resourceGoogleProjectService() *schema.Resource {
 				Type:         schema.TypeString,
 				Required:     true,
 				ForceNew:     true,
-				ValidateFunc: StringNotInSlice(append(ignoredProjectServices, bannedProjectServices...), false),
+				ValidateFunc: validateProjectServiceService,
 			},
 			"project": {
 				Type:             schema.TypeString,
diff --git a/google-beta/resource_google_project_service_test.go b/google-beta/resource_google_project_service_test.go
index af3d474c41..7d5719cb73 100644
--- a/google-beta/resource_google_project_service_test.go
+++ b/google-beta/resource_google_project_service_test.go
@@ -10,6 +10,44 @@ import (
 	"github.com/hashicorp/terraform-plugin-sdk/v2/terraform"
 )
 
+func TestProjectServiceServiceValidateFunc(t *testing.T) {
+	cases := map[string]struct {
+		val                   interface{}
+		ExpectValidationError bool
+	}{
+		"ignoredProjectService": {
+			val:                   "dataproc-control.googleapis.com",
+			ExpectValidationError: true,
+		},
+		"bannedProjectService": {
+			val:                   "bigquery-json.googleapis.com",
+			ExpectValidationError: true,
+		},
+		"third party API": {
+			val:                   "whatever.example.com",
+			ExpectValidationError: false,
+		},
+		"not a domain": {
+			val:                   "monitoring",
+			ExpectValidationError: true,
+		},
+		"not a string": {
+			val:                   5,
+			ExpectValidationError: true,
+		},
+	}
+
+	for tn, tc := range cases {
+		_, errs := validateProjectServiceService(tc.val, "service")
+		if tc.ExpectValidationError && len(errs) == 0 {
+			t.Errorf("bad: %s, %q passed validation but was expected to fail", tn, tc.val)
+		}
+		if !tc.ExpectValidationError && len(errs) > 0 {
+			t.Errorf("bad: %s, %q failed validation but was expected to pass. errs: %q", tn, tc.val, errs)
+		}
+	}
+}
+
 // Test that services can be enabled and disabled on a project
 func TestAccProjectService_basic(t *testing.T) {
 	t.Parallel()