2003 Twenty20 Cup
| Dates | 13 June 2003 – 19 July 2003 |
|---|---|
| Administrator(s) | England and Wales Cricket Board |
| Cricket format | Twenty20 |
| Tournament format(s) | Group stage and knockout |
| Champions | Surrey Lions (1st title) |
| Participants | 18 |
| Matches | 48 |
| Most runs | Brad Hodge (301 for Leicestershire) |
| Most wickets | Adam Hollioake (16 for Surrey) |
The 2003 Twenty20 Cup was the inaugural edition of what would later become the T20 Blast, England's premier domestic Twenty20 competition. The tournament ran from 13 June to 19 July 2003. All 18 first-class counties took part. The finals day took place on 19 July at Trent Bridge, and was won by the Surrey Lions.