| Dates | 2 July 2004 – 7 August 2004 |
|---|---|
| Administrator(s) | England and Wales Cricket Board |
| Cricket format | Twenty20 |
| Tournament format(s) | Group stage and knockout |
| Champions | Leicestershire Foxes (1st title) |
| Participants | 18 |
| Matches | 52 |
| Most runs | Darren Maddy (356 for Leicestershire) |
| Most wickets | Adam Hollioake (20 for Surrey) |
The 2004 Twenty20 Cup was the second edition of what would later become the T20 Blast competition, England's premier domestic Twenty20 competition.. The finals day took place on 7 August at Edgbaston, Birmingham, and was won by the Leicestershire Foxes.