1990–91 National Division 1

1990–91 National Division 1
Countries England
Date22 September 1990 – 27 April 1991
ChampionsBath (2nd title)
Runners-upWasps
RelegatedMoseley
Liverpool St Helens
Matches played78
Top point scorer126 – Rob Andrew (Wasps)
Top try scorer9 – Andrew Harriman (Harlequins)
Rory Underwood (Leicester)

The 1990–91 National Division 1 (sponsored by Courage Brewery) was the fourth season of the top tier of the English rugby union league system, the Courage Clubs Championship, currently known as Premiership Rugby. Wasps were the defending champions and Northampton and Liverpool St Helens the promoted sides.

Bath finished the season the champions for the second time, beating the holders Wasps by just one point. The two bottom sides, Moseley and Liverpool St Helens, were relegated to the 1991–92 National Division 2.