Jellia Jamb is a fictional character from the classic children's series of Oz books by American author L. Frank Baum. She is first introduced in The Wonderful Wizard of Oz (1900), as the head maid who works in the royal palace of the Emerald City which is the imperial capital of the Land of Oz. In later books, Jellia eventually becomes Princess Ozma's favorite servant out of the Emerald City's staff administration. She is also the protagonist of Ruth Plumly Thompson's novel Ozoplaning with the Wizard of Oz. Her name is a pun on the phrase "Jelly or jam?"