Princess Ozma is a fictional character in the Land of Oz universe created by L. Frank Baum. She appears in every book of the series except the first.

Daughter of the former King, she was given to the witch Mombi to hide by the Wizard. In The Marvelous Land of Oz she was installed as Oz's ruler, although many realms within Oz were unaware of her.

According to The Tin Woodman of Oz, Princess Ozma appears to be fourteen or fifteen years old, and several years older than Dorothy.

John R. Neill (1877 - 1943), the illustrator of Baum's Oz series, established the characteristic look of Ozma, strongly influenced by Charles Dana Gibson's 'Gibson girl' and by the beauties in the Art Nouveau poster art of Alphonse Mucha. Neill drew many pictures of Ozma between 1904, when she first appeared in The Marvelous Land of Oz, and his death in 1943, and during those years her image developed and changed. The illustration shown here is from Rinkitink in Oz, 1916 - about halfway through Ozma's gradual transformation from an angelic child to a spitfire glamour-girl.

Several fans have pointed out similarities in the appearance of Princess Leia from the Star Wars films to Ozma, in particular Leia's draped white costume and symmetrical hair design reminiscent of the flowers that typically adorn Ozma's crown.