He started his career with League of Ireland club St Patrick's Athletic before moving to Sheffield United in 2005. Quinn made over 200 appearances for the Blades, being their player of the season in 2011 and being in the Football League One PFA Team of the Year 2011–12. In 2012, he moved to Hull City and was a part of the team that won promotion back to the Premier League. Quinn also started the 2014 FA Cup Final against Arsenal. He is known for his set piece taking.