There are ten characters, including the judge, who is the killer in the story.
Dr. Armstrong - a doctor with a drinking problem who operated on a woman while he was drunk.
William Blore who pretends to be Mr. Davis is a private detective, a former police inspector
Miss Emily Brent - a religious fanatic, older woman, no occupation given who dismissed her pregnant servant
Very Claythorne - a Nanny, a child in her care drowned
Philip Lombard - a soldier for hire, a soldier of fortune
General Gordon Macarthur - a military man, a soldier
Anthony Marston - a playboy who has killed two children with his fast sports car
Isaac Morris - a shady businessman who made all the arrangements to bring the guests to Indian Island
Mr. & Mrs. Rogers - servants for hire, a sick woman died mysteriously while in their care
Judge Wargrave - A judge