The 1991 NCAA Division II men's basketball tournament involved 32 schools playing in a single-elimination tournament to determine the national champion of men's NCAA Division II college basketball as a culmination of the 1990-91 NCAA Division II men's basketball season. It was won by the University of North Alabama and Bridgeport's Lambert Shell was the Most Outstanding Player.
<nowiki>*</nowiki>denotes tie
Location: Andrew Laska Gymnasium Host: Assumption College
Location: Morrow Field House Host: Slippery Rock University of Pennsylvania
Location: CMSU Fieldhouse Host: Central Missouri State University
Location: CSUB Student Activities Center Host: California State University, Bakersfield
Location: Hyslop Sports Center Host: University of North Dakota
Location: Brayboy Gymnasium Host: Johnson C. Smith University
Location: Sartain Hall Host: Troy State University
Location: Kates Gymnasium Host: Ashland University
<nowiki>*</nowiki>denotes each overtime played
Location: Springfield Civic Center Hosts: American International College and Springfield College
<nowiki>*</nowiki>denotes each overtime played