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, Queen Margrethe II of Denmark and Queen Anne-Marie of Greece. From 1973 to 1979 he was heir presumptive to his nephew King Carl XVI Gustaf and the Swedish throne.