Prince Bertil, Duke of Halland (Bertil Gustaf Oskar Carl Eugén; 28 February 1912 – 5 January 1997), was a member of the Swedish royal family. He was the third son of King Gustaf VI Adolf and his first wife, Princess Margaret of Connaught, as well as the uncle of King Carl XVI Gustaf of Sweden. From 1973 to 1979, he was heir presumptive to his nephew Carl XVI Gustaf and the Swedish throne.