Stephen Farrelly ( born January 28 , 1978 ) is a Irish professional wrestler who currently wrestles for World Wrestling Entertainment working on its SmackDown brand and competes under the ring name Sheamus . Stephen Farrelly ( 28 January 1978 ) is an Irish professional wrestler and actor , best known by his ring names Sheamus and Sheamus O'Shaunessy . He is signed with World Wrestling Entertainment ( WWE ) and competes on the Raw brand where he is the reigning King of the Ring , and the current WWE United States Champion .