Neil Fingleton, the 7-foot 7-inch actor who played the giant Mag the Mighty on the hit HBO fantasy series “Game of Thrones,” died on Saturday. He was 36.

The Tall Persons Club said Mr. Fingleton, who was recognized by Guinness World Records in 2007 as Britain’s tallest man, died on Saturday, but did not say where he died. British news media reports said the cause was heart failure.

Mr. Fingleton, who was born in Durham, in northeast England, told the Guinness website in 2006 that he had “always been taller than everyone since I can remember.”

His height made him a natural for basketball, and he played college basketball in the United States for the University of North Carolina and the College of the Holy Cross in Worcester, Mass. He also briefly played professionally in an American minor league and in Europe before beginning his acting career.