Princess Margaretha of Sweden was a member of the Swedish Royal Family by birth and the Danish Royal Family by marriage. She was the elder sister of Crown Princess Märtha of Norway and Queen Astrid of the Belgians.

Princess Märtha of Sweden was Crown Princess of Norway as the spouse of the future King Olav V from 1929 until her death in 1954. The current king, Harald V, is her only son. As Olav only became king in 1957, Märtha never became Queen of Norway.