Thomas Thaddeus Hamilton (born April 3, 1975 in Chicago, Illinois) is a retired American NBA basketball player.
Hamilton attended Chicago's Martin Luther King High School, graduating in 1993. He was a high school teammate of Rashard Griffith (the 38th pick in the 1995 NBA draft) and the pair led their school to the 1993 Illinois State Basketball Championship.
The 7-foot, 2-inch, 330-pound center signed a letter of intent to play for Lou Henson at the University of Illinois, but was not academically eligible, and ultimately attended the University of Pittsburgh, though he did not play on the basketball team. In fact, Hamilton had never played basketball professionally (or in college) prior to the 1995–96 NBA season.
Hamilton was signed by the Boston Celtics at the beginning of the 1995–96 season but did not appear in a game until about five weeks remained in the regular season. He spent most of the season on both the injured and suspended lists. When he was fit to play, he appeared in 11 games and scored a total of 25 points. He averaged two rebounds and nearly one block per game in limited action. His weight was listed at 360 pounds when he taken off of the suspended list and appeared in his first NBA game. In his NBA debut on March 17, 1996, Hamilton had two points, two rebounds, and two blocked shots against the New Jersey Nets. He would score a career-high 13 points and grab six rebounds in only 12 minutes against the Washington Bullets on April 10, 1996.
Hamilton was signed by the Houston Rockets at the beginning of the 1999–2000 NBA season. He played in 22 games and made seven starts. He suffered a lower back strain and placed on the injured list for nearly two months until he was released on January 13, 2000. He averaged 12.4 minutes, 3.7 points, 4.1 rebounds, and 0.6 blocks per game with the Rockets.