The 2003 NCAA Division III men's basketball tournament was the 29th 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.

The field contained forty-eight teams, and each program was allocated to one of four sectionals.

All sectional games were played on campus sites, while the national semifinals, third-place final, and championship finals were contested at the Salem Civic Center in Salem, Virginia.

[1] Williams defeated Gustavus Adolphus, 67–65, in the championship, clinching their first national title.

Paulsen would later coach at Division I programs Bucknell and George Mason.