1998–99 National League 1
| 1998–99 National League 1 | |
|---|---|
| Countries | England |
| Champions | Henley (1st title) |
| Runners-up | Manchester (also promoted) |
| Relegated | Morley, Liverpool St Helens |
| Matches played | 182 |
The 1998–99 National League 1, sponsored by Jewson, was the twelfth full season of rugby union within the third tier of the English league system.
Henley finished the season as champions and along with runners up Manchester were promoted to Premiership Two. The relegated sides were Morley and Liverpool St Helens, both of whom would drop to National League 2 North.