is an Irish professional footballer who plays as an attacking midfielder for A-League Men club Brisbane Roar.

While he is primarily an attacking midfielder, he can also operate as a winger and striker. O'Shea began his career with St Joseph's Boys AFC before moving on to play for Home Farm of the Leinster Senior League in 2005. He signed for Bray Wanderers after just two appearances for Home Farm and spent a year and a half with Bray. In 2008, O'Shea signed for Galway United, playing 60 games for the club in all competitions, and attracted a lot of interest from English Football League and Premier League teams.

He subsequently joined Birmingham City in August 2009 for an undisclosed fee and made his Premier League debut shortly after against Manchester United. However, he found first-team opportunities hard to come by during his first season at Birmingham and was loaned out to Middlesbrough in March 2010. O'Shea was loaned out again in October 2010, this time to League Two side Stevenage where he spent two months, and then to Port Vale in January 2011. He was released when his contract expired at the end of the 2010–11 season and joined Milton Keynes Dons. He joined Chesterfield on loan in November 2012 and joined the club permanently two months later. He played for Chesterfield in the 2014 Football League Trophy final before helping them to win the League Two title in 2013–14. He was loaned out to Sheffield United in January 2017 and helped United to win the League One title in 2016–17. He signed with Bury in July 2017 and was named on the PFA Team of the Year as Bury secured promotion out of League Two at the end of the 2018–19 season. He moved to Australia in June 2019 to sign with A-League club Brisbane Roar. He was named in the PFA A-League Team of the Season in 2020–21 and 2022–23, and on the A-Leagues All Star in 2022.