The 1991 NCAA Division I softball tournament was the tenth annual tournament to determine the national champion of NCAA women's collegiate softball.
Held during May 1991, twenty Division I college softball teams contested the championship.
The tournament featured eight regionals of either two or three teams, each in a double elimination format.
The 1991 Women's College World Series was held in Oklahoma City, Oklahoma from May 23 through May 26 and marked the conclusion of the 1991 NCAA Division I softball season.
Arizona won their first championship by defeating three-time defending champions UCLA 5–1 in the final game.