Martin Henderson (born 8 October 1974) is a New Zealand actor, best known for his roles on the ABC medical drama Off the Map as Dr. Ben Keeton, the ABC medical drama Grey's Anatomy as Dr. Nathan Riggs, and for his performance as Noah Clay in the 2002 horror film The Ring, while remaining known in his home country for his teenage role as Stuart Neilson in the soap opera Shortland Street.
Henderson was born in Auckland, and began acting at the age of thirteen, appearing in Strangers, a local television production. He attended Birkenhead Primary and Westlake Boys High schools. He turned down going to study at University when he was 17, in favour of acting.
Henderson starred as Stuart Neilson in the prime-time soap opera Shortland Street from 1992 to 1995. He subsequently appeared in a number of Australian films and television productions including Echo Point and Home and Away, before moving to the United States in 1997, to pursue a career in Hollywood films and to train in a two-year program at the Neighborhood Playhouse in New York City.