To watch Hallmark Christmas movies, you'll need to have access to Hallmark Channel, either through cable TV or streaming services like Hulu or fuboTV. If you're using cable TV, you can find the channel in your guide and simply tune in during the times the movies are airing. If you're using a streaming service, you can search for Hallmark Channel within the app and select it to watch the movies. There are also many Hallmark Christmas movies available to rent or purchase online.