The 2021 Champion of Champions (officially the 2021 Cazoo Champion of Champions) was a professional snooker tournament that took place between 15 and 21 November 2021 at the University of Bolton Stadium in Bolton, England. It was the 11th Champion of Champions event, the first of which was held in 1978. The tournament featured 16 participants, primarily winners of significant tournaments since the previous year's event. As an invitational tournament, it carried no world ranking points.

Mark Allen was the defending champion, but he withdrew from the event for personal reasons. His place was awarded to Ding Junhui, the next eligible player on the world ranking list.

Judd Trump faced John Higgins in the final. Although Higgins took a 3–0 lead, Trump won ten of the next 11 frames to secure a 10–4 victory and his first Champion of Champions title with its prize of £100,000. Trump lost just five frames across the four matches he played in the tournament.

Qualification for the event was made through winning events from the previous year. Events shown below in grey are for players who had already qualified for the event. The 2021 World Snooker Championship runner-up Shaun Murphy was awarded a position in the event as well as remaining players being made up by the highest ranked players in the world rankings. Mark Allen, who had qualified as defending champion, withdrew prior to the event during the 2021 English Open.

A total of 12 century breaks were made during the tournament.