The 1990–91 Regal Trophy was a British rugby league knockout tournament. It was the 20th season that the competition was held, and was the second staging of the competition since it was re-named the Regal Trophy.

The final was won by Warrington, who beat Bradford Northern 12-2 in the match played at Headingley, Leeds. The attendance was 11,154 and receipts were £57662.

This season saw no changes in the entrants, no new members and no withdrawals, the number remaining at thirty-eight.

The preliminary round involved twelve clubs, to reduce the numbers to entrants to the first round proper to thirty-two.

^[1][2][3]

1 * Bradford Dudley Hill are a Junior (amateur) club from Bradford
2 * Saddleworth Rangers are a Junior (amateur) club from Oldham
3 * Egremont are a Junior (amateur) club from Cumbria
4 * At this time Fulham were a bit nomadic, using a collection of grounds as their "home", but the likelihood was that this match was probably played at Chiswick Polytechnic Sports Ground
5 * RUGBYLEAGUEproject^[1] and Rothmans yearbook 1991-92^[3] give the score as 6-35 but Wigan official archives^[5] gives it as 6-5, which must be a misprint as Batley were the team progressing to the next round
6 * Headingley, Leeds, is the home ground of Leeds RLFC with a capacity of 21,000. The record attendance was 40,175 for a league match between Leeds and Bradford Northern on 21 May 1947.

• 1990-91 Rugby Football League season
• 1990 Lancashire Cup
• 1990 Yorkshire Cup
• John Player Special Trophy
• Rugby league county cups