Chadwick began his career at Manchester United where he made 25 Premier League appearances in four seasons. While at Old Trafford he spent time out on loan at Reading and Burnley before joining West Ham United on a permanent basis in the summer of 2004. He spent a season with the Hammers before joining Stoke City on loan in August 2005 before making the move permanent in January 2006. He remained at Stoke until November 2006 making 55 appearances before joining Norwich City. Injuries restricted his time at Carrow Road and he moved to Milton Keynes Dons in October 2008. In March 2014, Chadwick joined Cambridge United, the club he supported as a child. He was released at the end of the 2014–15 season.