[5][6] From to 2002 to 2011, O'Riordan co-founded and ran the Ransom theatre company in Belfast, Northern Ireland, where she directed the production Hurricane.
The show was performed at the Edinburgh Festival Fringe and earned a season in London's West End and Off-Broadway in New York City.
[7] O'Riordan then completed a season with the Peter Hall Company, where she directed August Strindberg's Miss Julie, and an adaption of George Orwell's Animal Farm at the Theatre Royal in Bath, England.
[8] O'Riordan's tenure as artistic director of Ransom saw her commission and direct the first play by David Ireland, Arguments for Terrorism, and new plays Early Bird by Leo Butler and Transparency by Suzie Miller, Protestants by Robert Welch, and, the Irish famine-based This Piece of Earth by Richard Dormer.
[3][9] During this time she also ran a three-year programme entitled Writers on the Edge to develop new writing for women in Northern Ireland.