The 1990–91 Saint Francis Red Flash men's basketball team represented Saint Francis University during the 1990–91 NCAA Division I men's basketball season.

The Red Flash, led by fourth-year head coach Jim Baron, played their home games at the DeGol Arena and were members of the Northeast Conference.

They won the Northeast Conference tournament, their first, to advance to a play-in game against Fordham, which they also won, to secure a bid to the NCAA tournament.

The Red Flash fell in the opening round to Lute Olson's Arizona Wildcats.

As of 2022, this is their only NCAA tournament appearance.