The 2021 British Open (officially the 2021 Matchroom.live British Open) was a professional snooker event played from 16 to 22 August 2021 at the Morningside Arena, Leicester, England. It was the 2021 edition of the British Open event, and the first since the 2004 British Open. It was the second ranking event of the 2021–22 snooker season, following the 2021 Championship League and preceding the 2021 Northern Ireland Open. It was broadcast by ITV Sport in the UK, and sponsored by Matchroom Sport. The winner received £100,000 from a total prize pool of £470,000.
All rounds in the tournament were played after a random draw made under a single-elimination tournament format with no seeded players. The first four rounds, from the last 128 to the last 16, were played as best-of-five frame matches, the quarter-finals and semi-finals as best-of-seven-frame matches, and the final played as the best-of-eleven frames. John Higgins, the defending champion from 2004, lost 1–3 to Ricky Walden in the third round. Mark Williams defeated Gary Wilson 6–4 in the final to win the 24th ranking title of his career. The event featured 32 century breaks, including two maximum breaks. Higgins made his 12th maximum break in professional competition in the first frame of his first-round win over Alexander Ursenbacher, and Ali Carter made his third maximum break in the second frame of his fourth-round match against Elliot Slessor.