Steve McGarrett is a fictional character who is the protagonist of CBS' Hawaii Five-O. McGarrett is a former United States Navy officer and the leader of a special state police task force, which is called Five-O. McGarrett was portrayed by actor Jack Lord in the original show from 1968 to 1980, and later by Alex O'Loughlin in the series' remake from 2010. Throughout the show, McGarrett is partner to Detective Danny "Danno" Williams.