2015 One-Day Cup
| Dates | 25 July – 19 September 2015 |
|---|---|
| Administrator(s) | England and Wales Cricket Board |
| Cricket format | Limited overs cricket (50 overs) |
| Tournament format(s) | Group stage and knockout |
| Champions | Gloucestershire |
| Participants | 18 |
| Matches | 79 |
| Most runs | 531 Michael Klinger (Gloucestershire) |
| Most wickets | 20 Reece Topley (Essex) |
| Official website | ecb.co.uk |
The 2015 Royal London One-Day Cup tournament was the scheduled limited overs cricket competition for 2015 season of England and Wales first-class counties. It was won by Gloucestershire, who defeated Surrey by the narrow margin of six runs, despite a hat-trick from Jade Dernbach, in what was described as 'a thrilling finish'. The title was Gloucestershire's first trophy since the 2004 Cheltenham & Gloucester Trophy, when they defeated a Worcestershire side that included 2015 Surrey captain Gareth Batty.