Nicholas Simon O'Hern (born 18 October 1971) is an Australian professional golfer.
O'Hern has played on both of the world's premier professional golf tours, the European Tour, and the United States based PGA Tour. His biggest successes though, have come at home on the PGA Tour of Australasia, where he won the Order of Merit as the leading money winner in 2006.
O'Hern was born in Perth, Western Australia. His father was a three-handicap golfer who played baseball for Australia, and he followed him by playing baseball for Western Australia. He was also a talented tennis player, but he chose to concentrate on golf.