West Ham United Lee began his football career as a youth team player with
West Ham United, for whom he signed professionally in 2009. He made his debut in their 2–1 away defeat to
Exeter City on 2 April. His loan was extended until the end of the season, during which time he played in five league matches, all defeats, as the club failed to avoid
relegation to
League Two. The loan was later extended for a further two months. He made sixteen appearances in League Two and one in the
Football League Trophy, and scored three goals, all in the league.
Gillingham (first loan) After a two-week
trial in February 2012, Lee joined League Two club
Gillingham on loan for a month. He made his debut on 21 February in a goalless draw at home to
Rotherham United, and played eight matches in all during his loan spell, which was extended for a second month. West Ham released Lee when his contract expired at the end of
2011–12.
Barnet Mark Robson signed Lee for League Two club
Barnet on 3 July 2012. He played regularly at the start of the season, but increasingly infrequently after the arrival of
Edgar Davids as joint head coach, and not at all after Robson left the club.
Birmingham City (loan) Lee joined up with
Championship club
Birmingham City on trial in February 2013, and signed on loan on 21 March. He made no first-team appearances during his loan spell, but he was an unused substitute on the final day of the season, and captained the
under-21 development team.
Birmingham City Lee signed a permanent one-year contract with Birmingham City in May 2013, with the option of a further year, and no transfer fee was involved. He took part in pre-season friendlies with the first team, scoring against
Alfreton Town, With
Tom Adeyemi unavailable and
Callum Reilly unfit to start, both because of illness, Lee made his first appearance in the Championship at
Leeds United on 20 October and played the full 90 minutes as Birmingham lost 4–0. He and
Peter Løvenkrands entered the League Cup fourth-round match against
Stoke City as 79th-minute substitutes with Birmingham 3–1 down. Lee's 85th-minute free kick led to Løvenkrands pulling a goal back, and after the same player's equaliser took the match into extra time, Lee himself scored his first competitive goal for Birmingham, from outside the penalty area in the 118th minute to make the score 4–4, and converted his penalty in the
shootout, which Birmingham lost. He scored his first league goal for Birmingham, with a volleyed finish after
Nikola Žigić headed the ball down, on 15 February 2014 in a 2–1 defeat at home to
Huddersfield Town, and finished the season with 20 appearances, of which 16 were in Championship matches. He went straight into the starting eleven, and came close to scoring an equaliser from a free kick as Plymouth lost 1–0 at home to
Luton Town. He played seven matches during the month, scored once, a stoppage-time header with Argyle already 3–1 down at
Hartlepool United, and was
sent off in the last of the seven for a foul on Exeter City's
Tom Nichols. Despite the consequent three-match suspension, Lee's loan was extended to the end of the season. He made a further eight appearances for Argyle, but was forced to miss the end of the regular season, when Argyle qualified for the
play-offs, because of a groin injury. Birmingham confirmed he would be released when his contract expired at the end of the season.
Luton Town Lee signed for League Two club Luton Town on a short-term contract on 21 August 2015 which included performance-based options to lengthen his stay. He signed an extended contract until June 2017 on 22 September 2015. Lee helped Luton win promotion to League One in 2017–18. was voted the Mitre Goal of the Season at the 2018 EFL Awards.
Heart of Midlothian Lee signed a pre-contract agreement with
Scottish Premiership club
Heart of Midlothian in May 2018, and joined the club on a three-year contract upon the expiry of his contract with Luton. He scored in the 11th minute of his debut in a 2–1 away victory over
Cove Rangers in the
Scottish League Cup on 18 July 2018.
Gillingham (second loan) On 29 August 2019, Lee rejoined Gillingham, now in League One, on loan until 27 January 2020. The loan was extended until the end of the season on 9 January 2020. Lee returned to Hearts on 3 May 2020, and played regularly for them during the first part of the 2020–21 season. Lee scored in the penalty shoot-out as Hearts were defeated by Celtic in the
2020 Scottish Cup Final.
Gillingham (third loan) Lee rejoined Gillingham for a third loan spell in January 2021. Lee was in the Hearts team which won the Scottish Championship in the
2020–21 season.
Gillingham In June 2021, Lee signed a permanent contract with Gillingham. He retired from professional football in February 2023 due to struggles with
psoriatic arthritis and
Raynaud syndrome. ==Coaching career==