2003 ECB National League
| Administrator(s) | England and Wales Cricket Board |
|---|---|
| Cricket format | Limited overs cricket (45 overs per innings) |
| Tournament format(s) | League system |
| Champions | Surrey Lions (2nd title) |
| Participants | 19 |
| Matches | 162 |
| Most runs | 820 Michael Hussey |
| Most wickets | 34 Dimitri Mascarenhas |
The 2003 ECB National League season was a 45 over English county cricket competition; colloquially known as the Sunday League. Surrey Lions won the League for the second time.