Thomas Joseph "Tom" Thibodeau, Jr. (pronounced THIB-a-doe; born January 17, 1958) is an American basketball coach who last coached the Chicago Bulls. Since June 2013, he's served as an assistant coach for the USA Basketball Men's National Team.

As a defensive coach, he helped the Houston Rockets rank among the Top 5 in the league in scoring defense and field goal percentage defense from 2004 to 2007, and has helped his team finish in the league's Top 10 in team defense 15 times. He coached in 87 playoff games and was part of the 1999 NBA Finals as an assistant coach with the New York Knicks prior to joining the Boston Celtics, with whom he won the 2008 NBA Championship, serving as a defensive coach. In 2011 he was named the NBA Coach of the Year after leading the Bulls to a 62-win season. In 2012, he became the fastest coach in NBA history to earn 100 victories and finished as the runner-up for Coach of the Year.

College and early coaching career

Thibodeau played basketball at Salem State College, serving as captain during the 1980-81 season. During his time with the Vikings, the six-foot-two-inch Thibodeau helped Salem State to consecutive Division III national tournaments (1980–81). In 1980, Thibodeau helped Salem State to the league championship and the school's first NCAA Tournament bid. Upon graduating, he became an assistant coach at the school in 1981. In 1984, at the age of 25, he became head coach at Salem State after serving three years as an assistant. One season later he became an assistant coach at Harvard University, where he spent the next four seasons.