Whisker was a Thoroughbred racehorse that won the 1815 Epsom Derby and was a full-brother of the 1810 winner Whalebone. Whisker raced until he was a six-year-old, but did not race in 1817. Whisker was retired to stud in 1819, where he became a successful and influential sire. The offspring of Whisker and Whalebone continued the sire-line of Eclipse into the 20th century.

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.