The D.O.D. Festival is Ireland's biggest and longest running international heavy metal festival. The festival takes place over two days in early July each year in the County Laois village of Ballylinan and hosts a wide variety of bands from throughout Ireland and the rest of the world.

Originally held as the Day of Darkness Metalfest on June 22nd 2002 and headlined by Primordial the festival now attracts visitors and acts from all over the world. Among the acclaimed acts to have played the festival are Entombed, Candlemass, Destruction, Rotting Christ and Dismember.

The Festival has two goals - to attract top class international metal acts to an Irish metal festival and to give Ireland's many great indigenous metal acts the opportunity to showcase their material alongside their international peers.