Entertainment Weekly reports the actor will appear in the third season of the anthological series.
The third series will be witch-centric hence its title of Coven but its currently unclear what role O’Hare will play.
The actor played Larry Harvey in the first series of American Horror Story back in 2011. Other cast members confirmed for the third season including returning vets Jessica Lange, Sarah Paulson, Evan Peters, Frances Conroy and Lily Rabe while Kathy Bates will also appear.
O’Hare’s other notable credits include vampire king Russell Edgington in HBO‘s True Blood as well as stints in The Good Wife, Brothers & Sisters and CSI: Miami.
The premier date for American Horror Story: Coven is yet to be revealed by FX.