Williams joined Sunderland for a fee of £50,000 in October 1996,[2] and made over 250 appearances for the team, 108 of which were in the FA Premier League.

The highlight of his career so far was probably when he scored the winning goal for Sunderland at Middlesbrough, his hometown club, in 1997, effectively relegating the Teessiders.

Williams was also a part of the 1998 First Division play-off final defeat at Wembley Stadium, in which Sunderland were beaten by Charlton Athletic 7–6 on penalties after a 4–4 draw in regular play.

Williams joined Cardiff City on a month-long loan in September 2004, with a view to a permanent move if he impressed.

[6] After he was told by Sunderland manager Mick McCarthy his contract would not be extended,[7] Williams made his move to Ninian Park permanent in December 2004 on a free transfer.

[16] Williams joined Scottish Football League First Division side Dundee, where his former Sunderland teammate Alex Rae was manager, on trial in July 2008 and played for them in their opening game of the 2008–09 season as they defeated Ross County 2–1.

[23] Williams joined Conference North team Gainsborough Trinity on a contract until the end of the 2009–10 season on 12 March.

The Blues ended 2014–15 in 13th, but after a poor record of 3 wins in 21 league games, Williams was sacked on Monday 23 November 2015.