Born in Cork, O'Rourke attended University College, Dublin (UCD) where she held a sports scholarship between 2000 and 2004.

Also in 2003, she competed at her first World Athletics Championships in Paris before racing at her first Olympic Games in Athens, on both occasions failing to make it past the heats.

One week later, O'Rourke won the Bronze medal in the 100 m Hurdles at the World University Games in Izmir, Turkey in a time of 13.02 seconds.

O'Rourke competed for Ireland in the Women's 100-metre hurdles at the 2008 Summer Olympics held in Beijing, China: she failed to qualify from her heat, finishing sixth in a time of 13.22 s. O'Rourke showed a return to form in 2009, highlighted by her capturing of the bronze medal in the 60 m hurdles at the 2009 European Indoor Championships in Turin, Italy in a time of 7.97 s.[4] On 18 August 2009, O'Rourke qualified from her 100m hurdles quarter-final at the World Championships, coming in 2nd place in Heat 3 in a time of 12.86, a season's best.

[8] O'Rourke was selected to represent Europe in the 2010 IAAF Continental Cup (Formerly IAAF World Cup) making her the 5th Irish person and second female to be selected to represent Europe after John Treacy (7th in 1979), Eamonn Coghlan (Gold in 1981), John Doherty (Silver in 1991) and Sonia O'Sullivan (5th in 1994, and Gold in 1998).

After injury interrupted training O'Rourke competed in the 60m Hurdles at the 2011 European Athletics Indoor Championships in Paris.

A the 2011 World Championships in Athletics, O'Rourke finished second in her heat behind eventual champion Sally Pearson of Australia who clocked 12.53.

As her career wound down, O'Rourke picked up a fifth major medal - 60 m hurdles bronze at the 2013 European Athletics Indoor Championships in Gothenburg.

This medal, however, was not awarded to her until 2015 when initial gold medalist, Nevin Yanit, had her result rescinded following multiple doping violations.

[11] O'Rourke and her husband, two-time Olympian Peter O'Leary, welcomed their first child, daughter Dafne, in August 2015.