The 2005 World Snooker Championship was a professional snooker tournament that took place at the Crucible Theatre in Sheffield, England. The tournament started on 16 April, and ended on 2 May 2005. The event was the eighth and final world ranking event of the 2004–05 snooker season, following the 2005 China Open. The event was organised by the World Professional Billiards and Snooker Association. Due to laws banning advertising cigarettes in Great Britain, this was the last time the event was sponsored by the cigarette company Embassy. The event had a prize fund of £1,121,800, with the winner receiving £250,000.

Ronald Antonio O'Sullivan is an English professional snooker player. Widely recognised as one of the most talented and accomplished players in snooker history, he has won the World Snooker Championship seven times, a modern-era record he holds jointly with Stephen Hendry. He has also won a record eight Masters titles and a record eight UK Championship titles for a total of 23 Triple Crown titles, the most achieved by any player. He holds the record for the most ranking titles, with 41, and has held the top ranking position multiple times.