The blue-tailed monitor (Varanus doreanus), or Kalabeck's monitor is a member of the Varanidae family found throughout the Island of New Guinea, on the island of New Britain and in the Bismarck Archipelago. The Blue-tailed monitor is also found in Australia on the tip of the Cape York Peninsula. It belongs to the indicus group of the subgenus Euprepiosaurus. Varanus doreanus has not yet been evaluated by the IUCN .