1990–91 Courage League National Division Three
The 1990–91 Courage League National Division Three was the fourth full season of rugby union within the third tier of the English league system, currently known as National League 1. The division was increased by one team and they each played one match against the other teams, playing a total of twelve matches each.
Participating teams and locations
| Team | Ground | Capacity | City/Area | Previous season |
| Askeans | Broad Walk | Kidbrooke, London | 5th | |
| Broughton Park | Chelsfield Grove | Chorlton-cum-Hardy, Manchester | Promoted from Area League North | |
| Clifton | Station Road | 2,500 | Cribbs Causeway, Henbury, Bristol | Promoted from Area League South |
| Exeter | County Ground | 5,200 | Exeter, Devon | 6th |
| Fylde | Woodlands | 9,000 | Lytham St Annes, Lancashire | 8th |
| Lydney | Regentsholm | 1,500 | Lydney, Gloucestershire | 11th |
| Metropolitan Police | Imber Court | East Molesey, Surrey | Promoted from Area League South | |
| Morley | Scatcherd Lane | Morley, Leeds | Promoted from Area League North | |
| Nuneaton | Harry Cleaver Ground | Nuneaton, Warwickshire | 10th | |
| Roundhay | Chandos Park | Roundhay, Leeds West Yorkshire | 7th | |
| Sheffield | Abbeydale Park | 3,200 | Dore, Sheffield, South Yorkshire | 4th |
| Vale of Lune | Powderhouse Lane | Lancaster, Lancashire | 9th | |
| West Hartlepool | Brierton Lane | Hartlepool, Cleveland | 3rd |