No, you don’t need Google Mobile Services (GMS) to use Google’s ML Kit in all cases, but it depends on which features of ML Kit you plan to use.

If you are focusing on ML Kit's 'on-device capabilities', you won’t need GMS. However, for 'cloud-based features', GMS is required, as these rely on Google's services.

If you're developing for a non-GMS device (like certain Huawei devices), you may need to limit your app to ML Kit's on-device features or consider using another service for cloud-based ML features.