Career
O'Keefe began his career at Ipswich Town before being released in 2007. Southend United
He made his debut in the Football League against Leyton Orient on 20 January 2009 in the 1–1 away draw, coming on as a substitute in the 84th minute. O'Keefe made his first league start for Southend United against Leeds United at Elland Road on 27 January 2009.
He went on only made a handful of appearances for Southend. Crystal Palace
On 18 August 2010, O'Keefe signed for Crystal Palace after being recommended by former Southend player Dougie Freedman. In his first season O'Keefe was only a back up player and made four appearances.
In the 2011–12 season, O'Keefe was given a chance to impress early on in the season in the League Cup, he was an important part of the team that went on to play in the semi-final. Later on the season, O'Keefe was part of the end of season run in due to injuries. On 31 August 2013, O'Keefe sealed a 3-1 victory in Palace's first three points of their Premier League campaign in the 92nd minute at home to Sunderland with a curling 20 yard shot after coming on as a late substitute.
On 27 November 2014, O'Keefe joined Championship side Blackpool on loan until 1 January 2015. Cardiff City
On 28 January 2015 it was announced that O'Keefe had joined Championship club Cardiff City for an undisclosed fee, signing a two-and-a-half-year contract. He made his debut against Derby County three days later, in a 2–0 loss, following a string of disappointing results he was dropped to the bench for the remainder of the season, going on to make a further 6 appearances.
O'Keefe maintained a presence in the midfield, and eventually scoring his first goal for the club in the Severnside Derby against Bristol City in March.