diff --git a/moto/cloudformation/responses.py b/moto/cloudformation/responses.py
index cceedc86..c4a08570 100644
--- a/moto/cloudformation/responses.py
+++ b/moto/cloudformation/responses.py
@@ -351,18 +351,21 @@ class CloudFormationResponse(BaseResponse):
         return template.render(exports=exports, next_token=next_token)
 
     def validate_template(self):
-        cfn_lint = self.cloudformation_backend.validate_template(
-            self._get_param("TemplateBody")
-        )
+        template_body = self._get_param("TemplateBody")
+        template_url = self._get_param("TemplateURL")
+        if template_url:
+            template_body = self._get_stack_from_s3_url(template_url)
+
+        cfn_lint = self.cloudformation_backend.validate_template(template_body)
         if cfn_lint:
             raise ValidationError(cfn_lint[0].message)
         description = ""
         try:
-            description = json.loads(self._get_param("TemplateBody"))["Description"]
+            description = json.loads(template_body)["Description"]
         except (ValueError, KeyError):
             pass
         try:
-            description = yaml.load(self._get_param("TemplateBody"))["Description"]
+            description = yaml.load(template_body)["Description"]
         except (yaml.ParserError, KeyError):
             pass
         template = self.response_template(VALIDATE_STACK_RESPONSE_TEMPLATE)
diff --git a/tests/test_cloudformation/test_validate.py b/tests/test_cloudformation/test_validate.py
index 5ffaeafb..19dec46e 100644
--- a/tests/test_cloudformation/test_validate.py
+++ b/tests/test_cloudformation/test_validate.py
@@ -96,6 +96,25 @@ def test_boto3_yaml_validate_successful():
     assert response["ResponseMetadata"]["HTTPStatusCode"] == 200
 
 
+@mock_cloudformation
+@mock_s3
+def test_boto3_yaml_validate_template_url_successful():
+    s3 = boto3.client("s3")
+    s3_conn = boto3.resource("s3", region_name="us-east-1")
+    s3_conn.create_bucket(Bucket="foobar")
+
+    s3_conn.Object("foobar", "template-key").put(Body=yaml_template)
+    key_url = s3.generate_presigned_url(
+        ClientMethod="get_object", Params={"Bucket": "foobar", "Key": "template-key"}
+    )
+
+    cf_conn = boto3.client("cloudformation", region_name="us-east-1")
+    response = cf_conn.validate_template(TemplateURL=key_url)
+    assert response["Description"] == "Simple CloudFormation Test Template"
+    assert response["Parameters"] == []
+    assert response["ResponseMetadata"]["HTTPStatusCode"] == 200
+
+
 @mock_cloudformation
 def test_boto3_yaml_invalid_missing_resource():
     cf_conn = boto3.client("cloudformation", region_name="us-east-1")