21 - watch online: streaming, buy or rent
Currently you are able to watch "21" streaming on Netflix. It is also possible to buy "21" on Microsoft Store, Apple TV, Rakuten TV, Blockbuster, SF Anytime, Viaplay as download or rent it on Microsoft Store, Blockbuster, Apple TV, Rakuten TV, Viaplay, SF Anytime online.
There aren't any free streaming options for 21 right now. If you want know when it is streaming for free, click 'Free' in the filters above and hit the notification bell.