Season 21

Unreleased

The twenty-first season of began production on September 9, 2015. It is scheduled to begin airing on PBS on October 24, 2017.

This is the second season where the animation is entirely done by Oasis Animation, though it was produced at the same time as Season 20.

Together with Season 20, there will be 14 new 30-minute episodes. There will also be two one-hour specials that are not considered part of either season, though "Arthur and the Haunted Tree House" will premiere alongside new episodes of Season 21. This will most likely be the final season of the series. .