Sean Andrew Marks (born August 23 1975, in Auckland, New Zealand) is a professional basketball player with the NBA's Phoenix Suns. After attending Rangitoto College in Auckland, he moved to the United States in 1995 to play for the University of California, where he majored in political science, graduating with a BA degree in 1998. He is the first New Zealander to play in the NBA, and he represented New Zealand in international basketball tournaments, such as the 2000 and 2004 Olympic Games, and was part of their fourth place finish at the 2002 Basketball World Championship.

His international retirement came in 2004, but there are plans from new coach Nenad Vucinic to talk him out of international retirement.

Marks scored a career-high 16 points in San Antonio's February 8, 2006 win over the Toronto Raptors. In 2003-04, while also with the Spurs, he did not play a single second due to patella tendinitis. In 2000-01, he spent the season with Slask Wroclaw of Poland, and in December 2000 had an unsuccessful 10-day contract (10 days, 0 games) with the Seattle SuperSonics, returning to his Polish team until the season ended.

Marks is married to Jennifer, and has two sons, Aidan and Lucas.

Sean Marks signed with the Phoenix Suns on July 27, 2006 to a one-year contract, re-signing with the Arizona outfit on July 24, 2007.

Sean Marks became an American after he took the oath of U.S. citizenship in the downtown of Phoenix on November 30, 2007.