The 1981 Epsom Derby was the 202nd annual running of the Derby horse race. It took place at Epsom Downs Racecourse on 3 June 1981. The race was won by the Aga Khan's Shergar, at odds of 10/11 ridden by the nineteen-year-old jockey Walter Swinburn and trained at Newmarket, Suffolk by Michael Stoute. The winning margin of ten lengths was the largest in the history of the race. However, the winning time of 2:44.21 was the slowest since 1946.