Harold Tommy Amaker Jr. (; born June 6, 1965) is an American college basketball coach and the head coach of the Harvard University men's basketball team. He has also coached for the University of Michigan and Seton Hall University. He played point guard and later served as an assistant coach at Duke University under Mike Krzyzewski. An All-American player, Amaker set numerous records and earned many honors and awards. He took Seton Hall to the postseason in each of his four seasons as their coach, helped Michigan win the National Invitation Tournament the year after a probationary ban from postseason play, and had the three highest single-season win totals in the history of Harvard basketball, the school's first six Ivy League championships and first NCAA tournament victory.

Amaker was a high school basketball star at W. T. Woodson High School from 1979 to 1983 under coach Paul (Red) Jenkins. Amaker led the Woodson Cavaliers to four straight Northern District titles, including victories over the national powerhouse DeMatha Catholic High School. A McDonald's All-American, Amaker also earned the Wooden Defensive Player of the Year award in 1983, awarded to the nation's best high school defensive player. He averaged almost 18 points, and contributed 7.5 assists and 3.5 steals per game while at Woodson. In December 1992, the Connection named Amaker to the Connection Dream Team, as a point guard.McDonald's All-American and a Parade All-American. As a college basketball player, he set most of the assists records and many steals records for Duke basketball. He also set the Atlantic Coast Conference single-season games played and games started records. Among his numerous accolades, he was the first winner of the NABC Defensive Player of the Year, and he was a third team All-American.

Amaker was an assistant coach for the Duke Blue Devils men's basketball under Krzyzewski for nine seasons. His first four seasons were part of a five-year streak of Final Four appearances by Duke (including back-to-back national championships). As a head coach, Amaker took the Seton Hall Pirates to postseason tournaments (NCAA Division I men's basketball tournament and National Invitation Tournament [1998, 1999 and 2001]) in each of his four seasons as their coach. Assistant coach, Jason Lampa, credits the success that Amaker experienced at Seton Hall to his calm demeanor and respect for players. He dealt with the turmoil and self-imposed sanctions of the University of Michigan basketball scandal in his first years with Michigan, where he eventually won the 2004 National Invitation Tournament with the 2003–04 Michigan Wolverines men's basketball team and finished as the runner-up with Michigan in the 2006 National Invitation Tournament.

In his tenure as Harvard men's basketball coach, he was the first coach to lead the Crimson to victory over a ranked opponent with the school. He also coached the 2009–10 Harvard Crimson men's basketball team into the postseason (2010 CollegeInsider.com Tournament) in his third year there, which included the highest single-season victory total (21) in school history. In the summer of 2010, the NCAA ruled that Amaker had committed a recruiting violation, resulting in NCAA-mandated recruiting restrictions, the university's first NCAA penalty of the men's basketball program. The 2010–11 team became the first Harvard men's basketball team to clinch a share of the Ivy League championship and surpassed the prior season win total (23). The 2011–12 team became the first in school history to appear in the Associated Press (AP) and Coaches Polls and, for the third year in a row, established a new school record for wins (26). Amaker's 2011–12, 2012–13, 2013–14 and 2014–15 teams repeated as Ivy League champions. The 2012–13 team gave Harvard its first NCAA tournament victory. The 2013–14 team posted a record 27 wins. Amaker became the winningest coach in school history in 2016.

Early years Amaker was born in Falls Church, Virginia in 1965.

Amaker resided in Falls Church, but he attended W. T. Woodson High School in Fairfax, Virginia, because his mother, Alma Amaker, was a high school English teacher in Fairfax County. Her job allowed her to choose among the county schools, her choice made because the school's basketball coach, Red Jenkins, who called Amaker "T-bird", had been impressed with his performances at his youth summer league since Amaker was 10 years old. He began playing varsity for Woodson by December, making him the first freshman to play varsity in the school's history. His mother, whom Jenkins called "his first coach and his best coach," attended his practices and graded papers in the coach's office.

Duke University basketball head coach Mike Krzyzewski, who had just completed his first season as Duke coach, was in town to evaluate Johnny Dawkins 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." At the time, Amaker had wanted to play for the Maryland Terrapins because his sister Tami went to the University of Maryland, College Park and Amaker idolized Maryland star guard John Lucas. He was recruited eventually to Duke by assistant coach Chuck Swenson, who would later become an assistant coach during Amaker's first five seasons at Michigan from 2001 to 2006.

Amaker played on the 1983 McDonald's All-American Team and was also named to the Parade All-American team. According to the Fairfax Connection, the county changed the rules regarding where teachers could send their children due to Amaker's success at Woodson.

College career Amaker was a star point guard at Duke after becoming a freshman starter for head coach Krzyzewski. He led the team in assists three years and in steals four seasons. While at Duke his roommate for away games was Mike Brey.

Freshman and sophomore years Dawkins played point guard for the 1982–83 Blue Devils, but moved to shooting guard the following year to make way for Amaker. When Amaker joined the 1983–84 Blue Devils, unranked Duke, led by Dawkins and Amaker, won its first seven games, the longest winning streak of fourth-year head coach Krzyzewski's career. Amaker had a field goal accuracy of over 65 percent in those games. He led Duke to the NCAA Tournament during his 1984 freshman and 1985 sophomore seasons, but neither team advanced to the Sweet Sixteen (regional semifinals). In the quarterfinal round of the 1984 ACC men's basketball tournament against the Mark Price-led Georgia Tech Yellow Jackets, Amaker hit the game-winning shot with the score tied and less than 10 seconds left in overtime. In some instances, Amaker's defense changed the game by limiting dribble penetration and forcing low shooting percentages regardless of whether he had notable offensive contributions.

Junior year During Amaker's junior year (1985–86), Duke won the inaugural NIT Season Tip-Off (then known as the preseason National Invitation Tournament) and Amaker had nine assists in the championship game against a Danny Manning-led Kansas team. In the March Carolina–Duke rivalry game against North Carolina Amaker stole the ball from Jeff Lebo and made a layup that gave Duke a late first half three-point lead it never surrendered. The win clinched Duke's first regular-season ACC championship since 1966. According to ESPN college basketball color commentator Dick Vitale, Amaker had a reputation for putting pressure on the ball. That year, he helped the team win the 1986 ACC men's basketball tournament, including a championship game victory over the Price-led Georgia Tech.

Duke entered the 1986 NCAA tournament ranked number one with a team that was built around the defensive efforts of its guards, Dawkins and Amaker. In the final four with Duke clinging to a 69–67 lead in a rematch against Kansas, Amaker pulled down the final rebound and sank two clinching free throws in the final five seconds. The win sent Duke to the championship game, giving the team its 21st consecutive victory and an NCAA record 37 single-season victories. Chicago Tribune journalist Robert Markus described Amaker and Dawkins as the best guard combination in the country, although Vitale described Amaker as unknown.

The 1985–86 Blue Devils finished as national runner-up in the 1986 NCAA tournament to Louisville. That year, Amaker recorded 81 steals, second to Jim Spanarkel at that point in Duke history. He set the career steals record, which stood until Shane Battier broke it in 2001. Amaker also holds the Duke single-year NCAA tournament record with 18 steals in 1986, which had been a tournament record. That year, he had seven steals in two tournament games—against Old Dominion in the second round on March 15 and Louisville in the final on March 31. This seven-steal total stood as the single-game NCAA tournament record for seven years until the 1993 NCAA tournament when Darrell Hawkins had eight for Arkansas against Holy Cross and Grant Hill had eight for Duke against California. The seven steals was a championship game record that was tied by Mookie Blaylock in the 1988 NCAA tournament for Oklahoma against Kansas and was surpassed by Ty Lawson in the 2009 NCAA tournament for North Carolina against Michigan State. Amaker was selected to the 1986 Division I basketball tournament all-NCAA Final Four team. The 1986 Duke team graduated four of its five starters (Dawkins, Mark Alarie, Jay Bilas and David Henderson), leaving Amaker with an inexperienced supporting cast for his senior season. That year, Amaker was a spokesman against drug and alcohol abuse as part of an NCAA-Fiesta Bowl drug education television program.

Senior year Muggsy Bogues, Amaker's ACC rival, was his roommate during the July 1986 FIBA World Championship. He played in at least two games in the tournament, the first for a mere two minutes against Puerto Rico, but he played a prominent role in the USA's win over Italy. Amaker won a gold medal while serving on the US national team in the FIBA World Championship, which served as the basketball tournament for the 1986 Goodwill Games.

Senior Amaker served as team captain for the 1986–87 Blue Devils, and he led Duke back to the 1987 NCAA tournament, where they advanced to the Sweet Sixteen before losing to eventual champion Indiana. The key players on the team that year were Amaker and sophomore Danny Ferry. During his senior season, the National Collegiate Athletic Association instituted the three-point field goal. Amaker led Duke in three point shooting that year. He hit a three-point shot with 1:39 remaining in overtime against 17–0 (4–0 ACC) Horace Grant-led Clemson to give Duke the lead for good. A few weeks later, with the score tied in regulation at 60 against Notre Dame and on a two-on-one fast break with 16 seconds left, Amaker took a jump shot. Krzyzewski said Duke lost the game because it did not play as smart as its opponent and Markus described this example in his column. In Amaker's final home game, he made a jump shot with 1:15 remaining that put number seventeen Duke, which made all six of its free throws in the final 45 seconds, ahead for good in its rematch against number thirteen Clemson. In the 1987 tournament he led Duke in scoring in its final two games, including 23 against the Rick Calloway/Keith Smart/Steve Alford-led Indiana, who was coached by Bobby Knight, Krzyzewski's college coach.