Born in Falls Church, VA in 1963, Tommy attendend W.T. Woodson High School (Fairfax, VA). His mother chose for him to attend W.T. Woodson and play for fellow Washington Metropolitan Basketball Hall of Fame member, Coach Red Jenkins. Jenkins, who called Amaker "T-bird,"had followed him since age 10, through his impressive performances in youth summer leagues. He became the first freshman to play varsity in the school's history. Amaker received the Mr. Basketball Award (received at the Washington Metropolitan Basketball Hall of Fame dinner honoring 1983 NCAA Champion N.C. State) and was selected to the Capital All-Stars Team for the 10th Annual Capital Classic in 1983. The 1983 Capital Classic prophecy "Battle of the Guards," was borne out in a thrilling 2OT win by the Capital All-Stars 118-116 (Amaker was the leading scorer with 17). He also played on the 1983 McDonald's All-American Team and was named to the Parade All-American team.
Duke University basketball head coach Mike Krzyzewski, who had just completed his first season as Duke coach, was in town to evaluate Johnny Dawkins (Mackin, 1982 Capital All-Star) in a 1981 Washington D.C. summer league game, but was convinced to stay for a second game to see Amaker play. Krzyzewski met Amaker's mother and said, "Mrs. Amaker, your son is going to look great in Duke blue." Amaker played collegiately for Duke University, where he set many Duke career and single-season records.
Upon graduation, he immediatlely became an assistant coach for the Blue Devils under Mike Krzyzewski for nine seasons (1988-97). He then began his head coaching career at Seton Hall (1997-01), followed by Michigan (2001-07, 2004 National Invitation Tournament Champion, 2006 National Invitation Tournament Runner-up) and then Harvard University (2007-Present).