1999–2000 National League 1
| 1999–2000 National League 1 | |
|---|---|
| Countries | England |
| Champions | Otley (2nd title) |
| Runners-up | Birmingham & Solihull (also promoted) |
| Relegated | Reading, Blackheath |
| Matches played | 182 |
The 1999–2000 National League 1, sponsored by Jewson, was the thirteenth full season of rugby union within the third tier of the English league system.