The 1991 NCAA Division I Cross Country Championships were the 53rd annual NCAA Men's Division I Cross Country Championship and the 11th annual NCAA Women's Division I Cross Country Championship to determine the team and individual national champions of NCAA Division I men's and women's collegiate cross country running in the United States.

In all, four different titles were contested: men's and women's individual and team championships.

Held on November 25, 1991, the combined meet was hosted by the University of Arizona at El Conquistador Country Club in Tucson, Arizona.

The individual championship was won by Sean Dollman, from Western Kentucky, with a time of 30:17.1.

Villanova's Sonia O'Sullivan also repeated as individual national champion with a time of 16:30.3.