The Réunion harrier or Réunion marsh harrier (Circus maillardi) is a bird of prey belonging to the marsh harrier group of harriers. It is now found only on the Indian Ocean island of Réunion, where it is known locally as the papangue or pied jaune, although fossil material from Mauritius has been referred to this species. The Malagasy harrier (C. macrosceles) of Madagascar and the Comoro Islands was previously treated as a subspecies of this bird but is increasingly regarded as a separate species. The Réunion harrier appears to be declining in numbers and it is classed as an endangered species.