The distribution and taxonomy of varanid lizards occurring in the Bismarck Archipelago is revised on the basis of field surveys, examination of museum vouchers and molecular phylogenetic analyses. A total of four species is recorded: Varanus indicus and Varanus finschi on New Britain and some of its offshore islands, Varanus douarrha on New Ireland, Lavongai and Djaul, and Varanus semotus on Mussau Island. V. douarrha, previously mistaken for both V. indicus and V. finschi, is shown to be the only species represented on New Ireland and is here resurrected as a valid taxon based on an integrated approach combining morphological and molecular evidence. Phylogenetic analyses of two mitochondrial genes suggest that V. indicus is a relatively recent immigrant to the Bismarck Islands, whereas V. douarrha, V. finschi and V. semotus have significantly longer histories in the island group. Together with the recently described V. semotus the revalidation of V. douarrha doubles the number of species known to occur in the Bismarck region and highlights an important component of both local and regional endemism.