Robert, Earl of Burlesdon, is a minor character in The Prisoner of Zenda, appearing only at the very beginning and the very end of the narrative. His younger brother, Rudolf Rassendyll, is the protagonist and narrator. In terms of appearance, there is a major difference between them, which is an important plot point. Robert has black hair, which has always been the mark of the Rassendyll family. However, Rudolf's hair is flaming red, showing his descent from the royal house of Elphberg. He also has the typical Elphberg nose.

In terms of character, Robert and Rudolf are both quintessentially honorable English gentlemen, chivalrous and polite. However, Robert is rather a quiet and dull politician with a settled family life. Rudolf, at the beginning of the novel, is an idler who does nothing, because, being a member of a wealthy family, he does not need to work.

During the course of the novel, he discovers a strong taste for adventure and romance, which was clearly always latent in him. He also shows physical courage and coolness under pressure. He is even less inclined to settle down to a conventionally respectable life at the end of the novel than he was at the beginning and will clearly never follow Robert into a career in public life.