Surplice (1845–1871) was a British Thoroughbred racehorse and sire. In a career that lasted from July 1847 to October 1849 he ran thirteen times and won nine races. He was the leading colt of his generation in England at both two and three years old, with his wins including The Derby and the St Leger in 1848: he was the first horse for forty-eight years to win both of these Classics. His later career was less successful and he was retired to stud in 1850. Surplice had limited success as a sire of winners and died in 1871.

The Derby Stakes, also known as the Derby or the Epsom Derby, is a Group 1 flat horse race in England open to three-year-old colts and fillies. It is run at Epsom Downs Racecourse in Surrey on the first Saturday of June each year, over a distance of one mile, four furlongs and 10 yards, or about 1½ miles. It was first run in 1780.