The 1991 NCAA Division III Men's Basketball Tournament was the 17th annual single-elimination tournament to determine the national champions of National Collegiate Athletic Association (NCAA) men's Division III collegiate basketball in the United States. Held during March 1991, the field included forty teams. The championship rounds were contested in Springfield, Ohio. Wisconsin–Platteville (28–3) defeated Franklin & Marshall, 81–74, to clinch their first NCAA Division III national title.