Born in Oxford, Lee joined the academy at Watford at the age of 11 from Bedgrove Dynamos and progressed through the ranks to become a reserve team regular during the 2001–02 season,[3][4] learning from player-goalkeeping coach Kevin Hitchcock.
[5] Incoming manager Ray Lewington promoted Lee to second-choice goalkeeper ahead of Espen Baardsen for the 2002–03 season and he made his senior debut in a 1–0 defeat to Preston North End on 4 March 2003.
[12] He played in every match of the Hornets' run to the League Cup semi-finals, but he missed the two-legged tie against Liverpool due to a broken cheekbone suffered in a defeat to Coventry City a month previously.
[13] Out of favour with Watford manager Aidy Boothroyd, Lee joined Premier League club Blackburn Rovers on loan until the end of the 2005–06 season on 25 August 2005.
[7] Behind Ben Foster and Alec Chamberlain in the pecking order, Lee made just 14 appearances during the 2006–07 season and the Hornets were relegated straight back to the Championship.
[18] Save for a run of 11 matches from September through to November 2008, Lee spent the 2008–09 season battling with Mart Poom for the position of second-choice goalkeeper behind Scott Loach.
[19] He signed a new one-year contract extension in May 2009, but spent the entire 2009–10 season behind Scott Loach in the pecking order and made just two League Cup appearances in August 2009.
[24] He spent the early months of the season behind Simon Moore and loanees Alex McCarthy and Ben Hamer in the pecking order and appeared only in cup matches.
[43] He stated that the move was purely on an emergency basis and manager Alan Dowson later commented that Lee had "not committed to training and is just looking after himself in his spare time".
[44][45] In late November 2017, Lee came out of retirement to join Southern League Premier Division club Dunstable Town as one-match cover for loan goalkeeper Nick Hayes.
[56] The same year, Lee enrolled on a two-year PFA degree in Professional Sports Writing and Broadcasting at Staffordshire University, from which he graduated with honours in July 2014.
[59] After retiring from professional football in May 2015, Lee began contributing to Sky Sports' Soccer Saturday as a pundit and reporter and working as a motivational speaker.
[60][61] On 31 August 2006, Lee appeared on the BBC programme Dragons' Den, where he and a partner managed to sell 50% of the equity in their company Dr. Cap to the entrepreneur Duncan Bannatyne for an investment of £150,000.