North Brother Island is an uninhabited island in the Indian Ocean, part of the Andaman Archipelago. It is located in the Duncan Passage, about 19 kilometre northeast of Little Andaman Island. It is part of the South Andaman district of the Andaman and Nicobar Islands, a Union Territory of India. By the end of the 19th century, the island was occasionally visited by the Onge of Little Andaman to catch sea turtles.It has been conjectured to be part of the route for the Onge expansion into south Great Andaman Island in the wake of the Great Andamanese tribes, around 1890 to 1930.