"Peter Killian Gallagher" is an American actor, musician and writer. Since 1980, Gallagher has played roles in numerous Hollywood films. He starred as Sandy Cohen in the television drama series The O.C. from 2003 to 2007. Since 2011 appears in a recurring role on the USA Network drama Covert Affairs, as CIA Clandestine Services Director Arthur Campbell.If you enjoy these quotes, be sure to check out other famous actors! More Peter Gallagher on Wikipedia.