St. Thomas Aquinas High School offers a wide variety of co-ed sports programs, with 29 varsity teams, as well as 13 junior varsity programs and 9 Freshman teams. On a yearly basis, well over fifty percent of Saint Thomas students participate in at least one sport.

The St. Thomas Aquinas "SAINTS" compete in Division 2 of the New Hampshire Interscholastic Athletic Association. The school participates in Division 1 in Men's Hockey, plays in Division 2 in Volleyball, Swimming, Alpine Skiing, Women's Ice Hockey, and Lacrosse (Men's and Women's), Wrestling is Division 3, and in Division 5 Football.

Freshmen will find our sports programs to be a wonderful opportunity to improve their individual skills, work toward team goals and make new friends. Players of greater skill will find our varsity programs challenging and competitive. Since 2000, St. Thomas has won 36 individual and 21 team State Championships.