Alex O'Loughlin (born Alexander O'Lachlan; 24 August 1976) is an Australian actor, currently starring in CBS's Hawaii Five-0 as Lieutenant Commander Steve McGarrett. His earlier roles include Kevin Hiatt in The Shield, Mick St. John in Moonlight, Dr. Andy Yablonski in Three Rivers, and Stan in The Back-up Plan. He is also the current ambassador for Donate Life America.