The Chatham Islands rail (Cabalus modestus), also known as the Chatham rail is an extinct flightless species of bird in the family Rallidae. It was endemic to Chatham, Mangere and Pitt Islands, in the Chatham archipelago of New Zealand. The Chatham Islands rail was first discovered on Mangere in 1871, and 26 specimens collected there are known from museum collections. Its Māori name was "mātirakahu".