1989–90 Courage League National Division Three
The 1989–90 Courage League National Division Three was the third full season of rugby union within the third tier of the English league system, currently known as National League 1. Each team played one match against the other teams, playing a total of eleven matches each. Following their relegation the previous season, London Scottish won all their eleven matches and won promotion with three matches remaining, to return to National Division Two. Wakefield finished second and were also promoted. London Welsh finished in last place and was relegated to Area League South for the following season.
Participating teams and locations
| Team | Ground | Capacity | City/Area | Previous season |
| Askeans | Broad Walk | Kidbrooke, London | 8th | |
| Exeter | County Ground | 5,200 | Exeter, Devon | 9th |
| Fylde | Woodlands | 9,000 | Lytham St Annes, Lancashire | 10th |
| London Scottish | Athletic Ground | 4,500 | Richmond, London | Relegated from Courage League Division 2 |
| London Welsh | Old Deer Park | 5,850 | Richmond, London | Relegated from Courage League Division 2 |
| Lydney | Regentsholm | 1,500 | Lydney, Gloucestershire | Promoted from Area League South |
| Nuneaton | Harry Cleaver Ground | Nuneaton, Warwickshire | 5th | |
| Roundhay | Chandos Park | Roundhay, Leeds West Yorkshire | Promoted from Area League North | |
| Sheffield | Abbeydale Park | 3,200 | Dore, Sheffield, South Yorkshire | 6th |
| Vale of Lune | Powderhouse Lane | Lancaster, Lancashire | 7th | |
| Wakefield | College Grove | 3,000 | Wakefield, West Yorkshire | 3rd |
| West Hartlepool | Brierton Lane | Hartlepool, Cleveland | 4th |