The story's main characters are the Canterville Ghost and the Otis family.
The Canterville Ghost, a former English lord named Sir Simon, murdered his wife centuries ago. For this crime, he is forced to walk the earth as a ghost. His job is to haunt Canterville Hall and frighten the residents. He would like to go to his final rest and stop being a ghost, but he needs someone of purity and faith to intercede and pray for him to die.
The Otis family consists of Mr. Hiram Otis, Mrs. Lucretia Otis, and their four children. They have one daughter, a beautiful teenage girl named Virginia, and three sons. Washington is the oldest child in the family and the twin boys, called Stars and Stripes, are the youngest. Being practical, hard-headed Americans without much sense of tradition, they do not believe in ghosts. Even when they realize the ghost is real, they are not afraid of it. Star and Stripes play so many practical jokes on Sir Simon that he is frightened of them.
Minor characters include Mrs. Umney, the housekeeper, and the young Duke of Chehsire, who falls in love with Virginia.