Glossop born Keith was a box to box midfielder. He started his career as a trainee with Stockport County in 1999, going on to make nearly 70 appearances for the Hatters. He was signed by Norwich for £65,000 in January 2003, but could not command a first team place (with three appearances), being sent on loan to Crewe Alexandra, before eventually being released in 2004, upon which, he joined Stockport County again. He took his total appearances for County up to 166, before joining Shrewsbury Town for two games, and then Mansfield Town in February 2008. Although Mansfield wished to retain his services, Keith returned closer to his home town, and joined Celtic instead.

Keith spent two years with Celtic, but when Steve Burr made his sensational move to Kidderminster, Keith followed. He made eighty-three appearances for the Harriers, between 2010 and 2013, but had a year at Fleetwood sandwiched in there when he made seventeen appearances between 2011 and 2012.

After the departure of manager Jim Harvey in 2013, Keith returned as player/manager, not just to lead on the pitch, but also off it. He took the helm for the remainder of the 13/14 season, with his first full season to follow. Despite switching back from the disasterous Youth Policy of his predecessor, results didn't improve, and he tendered his resignation in 2015 (going onto work at Southport), to be succeeded by Liam Watson. In 2017, after Celtic's relegation to the Northern Premier League, Keith returned, this time as assistant to Steve Burr, but after a few months was offered a full time role at Sheffield United, and could not turn it down.