Thai police told the BBC the 72-year-old was found by a hotel maid sitting in a wardrobe with a cord around his neck and other parts of his body.
The US star was in Thailand filming his latest film, Stretch, according to his personal manager Chuck Binder.
Mr Binder said the news was "shocking", adding: "He was full of life, always wanting to work... a great person."
A US embassy official confirmed the actor's death, but added that the cause of death had not yet been established.
RIP David Carradine.