Leicester City Sheehan joined
Leicester City in July 2003 after being spotted by a scout whilst playing for
Belvedere. He initially played for the club's youth team and joined
Mansfield Town on loan to gain first team experience. and his second in a 3–2 win over
Nottingham Forest on 18 September. Following Leicester's 2–0 victory over
Bristol City on 24 November, Sheehan was named in the
Championship Team of the Week. He made 20 league starts in the senior team for Leicester. having rejected a new contract offer from Leicester. He made his Leeds debut in a 2–0 defeat to
Tranmere Rovers on 2 February 2008, replacing
Ben Parker at left back. Sheehan scored his first goal for Leeds in their 1–0 win over
Doncaster Rovers on 1 April 2008. Sheehan was
sent off in Leeds' 1–0 win over
Yeovil Town for a two-footed tackle on
Zoltán Stieber. The straight
red card meant he was
suspended for both legs of the play-off semi-final against
Carlisle United. After Leeds lost the play-off final against Doncaster Rovers, Sheehan signed permanently for Leeds on 1 July 2008. He scored a long range goal against
Crewe Alexandra in a 5–2 win, but was sent off for another two-footed tackle in a match against
Swindon Town.
Loan spells In March 2009, Sheehan joined Crewe Alexandra on loan for the rest of the season. He made his debut in the 2–2 draw with
Milton Keynes Dons. The following season, he joined
League One club
Oldham Athletic on a one-month loan and made his league debut for Oldham on 4 September in a 3–0 home defeat to Hartlepool United. Sheehan gained two assists in a 2–0 win over Carlisle United and scored his first Oldham goal in a 2–1 win over Milton Keynes Dons on 29 September 2009. On 2 October 2009, his loan was extended until 1 November. On 26 November 2009, Sheehan joined League One club Swindon Town on loan and made his debut in the
FA Cup match against
Wrexham. Swindon faced
Charlton Athletic in the League One play-offs; Sheehan played in the first leg, which Swindon won 2–1, but he missed the second leg through injury. Sheehan returned to play in the play-off final defeat to
Millwall, and was substituted after 67 minutes after aggravating his injury. On 31 August 2010, Sheehan signed for Swindon from Leeds on a one-year deal.
Notts County and Bradford City In July 2011, Sheehan left Swindon to join League One club
Notts County on a two-year contract. Sheehan was made club
captain during the
2013–14 campaign and was awarded Player of the Year towards the end of the season. After making more than 100 appearances for Notts County, Sheehan signed for League One club Bradford City on a free transfer in June 2014. He was signed by manager
Phil Parkinson for his ability to play left back and centre back. Sheehan scored a penalty on his league debut, a 3–2 home win over
Coventry City. On 26 March 2015, Sheehan moved on a short-term loan to League One club
Peterborough United until the end of the
2014–15 season. At the start of the
following season, Sheehan made two league appearances for Bradford City and returned to Notts County on a three-month loan. While at Notts County, Sheehan scored the winning goal in the club's 2–1 win against
Portsmouth, which was the sixth league win in seven games for Notts County.
Luton Town On 22 January 2016, Sheehan signed for
League Two club
Luton Town on loan from Bradford until the end of
2015–16. He scored a
volley, his only goal during his loan spell for the club, in a 1–1 draw with
Yeovil Town on 2 February 2016. Sheehan played in every match, making 20 league appearances for the club during his loan spell. His contract was extended by a further year at the end of the
2017–18 season after a promotion clause was triggered as a result of Luton's
promotion to League One. Sheehan then signed a new two-year contract with Luton at the end of May 2018. He was named in the League Two
PFA Team of the Year for 2017–18 and was awarded Luton's Player of the Year. The following season, Luton were promoted to the Championship with Sheehan as club captain. He reached an agreement with Luton over the final six months of his contract and was released as a free agent on 31 January 2020.
Later career and retirement Sheehan signed for League One club
Lincoln City on 2 March 2020 on a contract until the end of the
2019–20 season. He then joined League One club
Northampton Town on 27 October 2020 on an appearance-based contract. Sheehan re-signed for Oldham Athletic as a
player-coach on 23 July 2021 on a one-year contract, before retiring from playing in January 2022. ==International career==