diff --git a/moto/cognitoidp/models.py b/moto/cognitoidp/models.py
index e203fe303..8d6cabd1d 100644
--- a/moto/cognitoidp/models.py
+++ b/moto/cognitoidp/models.py
@@ -1800,6 +1800,15 @@ class GlobalCognitoIdpBackend(CognitoIdpBackend):
     # Without authentication-header, we lose the context of which region the request was send to
     # This backend will cycle through all backends as a workaround
 
+    def _find_backend_by_access_token(self, access_token):
+        for region, backend in cognitoidp_backends.items():
+            if region == "global":
+                continue
+            for p in backend.user_pools.values():
+                if access_token in p.access_tokens:
+                    return backend
+        return cognitoidp_backends["us-east-1"]
+
     def _find_backend_for_clientid(self, client_id):
         for region, backend in cognitoidp_backends.items():
             if region == "global":
@@ -1821,6 +1830,10 @@ class GlobalCognitoIdpBackend(CognitoIdpBackend):
         backend = self._find_backend_for_clientid(client_id)
         return backend.confirm_sign_up(client_id, username)
 
+    def get_user(self, access_token):
+        backend = self._find_backend_by_access_token(access_token)
+        return backend.get_user(access_token)
+
 
 cognitoidp_backends = BackendDict(CognitoIdpBackend, "cognito-idp")
 cognitoidp_backends["global"] = GlobalCognitoIdpBackend("global")
diff --git a/moto/cognitoidp/responses.py b/moto/cognitoidp/responses.py
index f67734c37..bf6b46b7b 100644
--- a/moto/cognitoidp/responses.py
+++ b/moto/cognitoidp/responses.py
@@ -346,7 +346,7 @@ class CognitoIdpResponse(BaseResponse):
 
     def get_user(self):
         access_token = self._get_param("AccessToken")
-        user = cognitoidp_backends[self.region].get_user(access_token=access_token)
+        user = cognitoidp_backends["global"].get_user(access_token=access_token)
         return json.dumps(user.to_json(extended=True, attributes_key="UserAttributes"))
 
     def list_users(self):
diff --git a/tests/test_cognitoidp/test_server.py b/tests/test_cognitoidp/test_server.py
index c904058cd..a92d55d28 100644
--- a/tests/test_cognitoidp/test_server.py
+++ b/tests/test_cognitoidp/test_server.py
@@ -55,3 +55,42 @@ def test_sign_up_method_without_authentication():
     )
     res.status_code.should.equal(200)
     json.loads(res.data).should.have.key("UserConfirmed").equals(False)
+
+    # Confirm Sign Up User
+    data = {
+        "ClientId": client_id,
+        "Username": "test@gmail.com",
+        "ConfirmationCode": "sth",
+    }
+    res = test_client.post(
+        "/",
+        data=json.dumps(data),
+        headers={"X-Amz-Target": "AWSCognitoIdentityProviderService.ConfirmSignUp"},
+    )
+
+    # Initiate Auth
+    data = {
+        "ClientId": client_id,
+        "AuthFlow": "USER_PASSWORD_AUTH",
+        "AuthParameters": {"USERNAME": "test@gmail.com", "PASSWORD": "12345678"},
+    }
+    res = test_client.post(
+        "/",
+        data=json.dumps(data),
+        headers={"X-Amz-Target": "AWSCognitoIdentityProviderService.InitiateAuth"},
+    )
+    res.status_code.should.equal(200)
+    access_token = json.loads(res.data)["AuthenticationResult"]["AccessToken"]
+
+    # Get User
+    data = {"AccessToken": access_token}
+    res = test_client.post(
+        "/",
+        data=json.dumps(data),
+        headers={"X-Amz-Target": "AWSCognitoIdentityProviderService.GetUser"},
+    )
+    res.status_code.should.equal(200)
+    data = json.loads(res.data)
+    data.should.have.key("UserPoolId").equals(user_pool_id)
+    data.should.have.key("Username").equals("test@gmail.com")
+    data.should.have.key("UserStatus").equals("CONFIRMED")