No, you can stream movies, TV shows and more on a Roku® streaming player or Roku TV™ without a traditional cable or satellite subscription. In fact, many Roku customers have “cut the cord” meaning that they have no cable or satellite subscription and their Roku streaming device is the primary way they watch television.
However, many Roku customers do have a cable or satellite subscription. There are some Roku channels that are only available to customers with a cable or satellite subscription; these are known as authenticated channels or TV Everywhere channels. TV Everywhere channels offer subscribers access to additional content on their Roku device as part of their cable or satellite subscription. For example, if you subscribe to ESPN, then you can access additional ESPN content by downloading Watch ESPN from the Roku Channel Store.
TV Everywhere channels are published by the network (e.g. ESPN, HBO, Showtime, etc.) and not the cable company (e.g. Comcast, Time Warner, etc.). However, some cable/satellite companies are creating Roku streaming channels that allow you to access all or most of the channels you get through your cable subscription without having a separate cable box (e.g. Spectrum TV, Comcast Xfinity, DIRECTV NOW).