The 1998 NCAA Division III men's basketball tournament was the 24th 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.

Each of these forty-eight programs were allocated to one of four sectionals of twelve teams.

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] Wisconsin–Platteville defeated Hope, 69–56, in the final, clinching their third overall national title and third championship in seven seasons (1991 and 1995).

Ben Hoffmann, also from Platteville, was named Most Outstanding Player.