Is their a way to watch an Amazon movie offline through a roku stick?

Exactly no, u can stream Amazon Prime Video content directly on your Roku stick while connected to the internet, but offline viewing is not supported. Or u can use some tools like Tunepat Videogo All-in-One which can help you download unlimited Amazon movies and shows without ads. What’s more, u can store the downloads forever on your computer or move them to other devices for offline viewing. Therefore, it’s avaliable for u to cast them to your Roku TV freely for offline viewing without ad interruptions. It’s really feasible. Have a try!