The boys’ basketball program has the benefits of a classic, old-school gym and a committed school community that regularly fills it with energy, excitement, and support. Each year, the boys' varsity basketball team plays a demanding non-league schedule to prepare it for the tight competition that league play presents. Focusing on skillful execution, teamwork, sportsmanship, and the tenacity to overcome any challenge, students find success and growth on the court, win or lose. About those wins, though: Voit Gym holds memories of countless victories, and Thacher’s boys' basketball history is filled with many league championships and California Interscholastic Federation (CIF) playoff berths.

The varsity team has won multiple league titles in recent years and made 14 consecutive trips to the CIF playoffs. In 2007, 2008, 2013, and 2020 the team advanced to the CIF quarterfinal round—often pulling off huge upsets along the way—and in three instances, Thacher was eventually eliminated by the #1 seed. 

Recent Thacher graduates have continued playing basketball for the following Division III colleges: Carnegie Mellon, Kenyon, Pomona-Pitzer, and Swarthmore.