| Derby | |
 Diomed by George Stubbs (1724–1806) | |
| Location | Epsom Downs |
|---|---|
| Date | 4 May 1780 |
| Winning horse | Diomed |
| Starting price | 6/4 |
| Jockey | Sam Arnull |
| Trainer | R Teasdale |
| Owner | Sir Charles Bunbury |
| Conditions | not known |
The 1780 Epsom Derby was the inaugural running of The Derby – the horse race which would become the "greatest turf event in the world"[1] and after which more than 140 other horse races,[2] including the famous Kentucky Derby, are named. It took place on 4 May 1780 on Epsom Downs in Surrey,[2] England, and was won by Diomed, owned by Sir Charles Bunbury and ridden by Sam Arnull.