O'Connor went to Wheelers Lane Boys School in Birmingham between 1996 and 2001. P.E teacher Mr Alan Miller joined the Aston Villa youth set-up in 1997 and recommended O'Connor who then was known as a creative midfield player. He joined Aston Villa and established himself as a strong defender. He featured in the 2002 FA Youth Cup win. He missed the first leg of the semi final but returned to face a Wayne Rooney inspired Everton in the final after a car crash early in the year had ruled him out for a number of months. A loan spell at Port Vale allowed him to gain first team experience.
Not making the grade however at Aston Villa, he joined Bournemouth on loan at the start of the 2004/2005 season and in January 2005 joined for an undisclosed fee. O'Connor quickly became an integral part of the team and first team regular, making his name as a tough tackler and promising player.
In May 2006 he was sold to Doncaster Rovers for £130,000 due to Bournemouths financial difficulties. He made a very good start to his Rovers career in the 2006/7 season with consistent performances throughout the season in defence. In the 2007/8 season, O'Connor really began to excel in the Doncaster side, playing in the right-back slot, providing width and speed to the Rovers attacks, as well as playing his part as a key player in a solid defence. O'Connor has scored one goal so far in his Doncaster career, the third goal in a resounding 4-0 victory away at Brentford in December 2006.
O'Connor pledged his future to Doncaster Rovers in July 2008 by signing an extension to his contract. His new deal runs until 2011.