At the UK Championship, Walden reached the last 16 after knocking out Rod Lawler, Ashely Carty, and Mark Williams before losing to Judd Trump. His best result of the season came in the Scottish Open, in which he advanced to the quarter-final after beating the likes of Tom Ford and Mark Allen before losing to the eventual champion Mark Selby. In April 2021, Walden qualified for the World Snooker Championship for the first time in 3 years after beating Peter Lines and Ryan Day in the qualifying rounds. He drew Anthony McGill in the first round.
