The 17-year-old was found unconscious in his dorm in Leicestershire on Sunday and taken to hospital, where he died on Tuesday, the BBC has been told.
He had been enrolled in a football academy in the UK since late last year.
He was captain of the Thai boys' football team, which was trapped deep inside a cave for over two weeks while exploring in Chiang Rai province.
His grinning face, caught by the torch light of a diver after the boys were found in the cave, was one of the most memorable images from the rescue.
