Batrachomatus nannup is a species of diving beetle in the family, Dytiscidae, first described as Allomatus nannup in 1978 by Chris H.S. Watts.[1] [2] [3] The holotype was collected in Bridgetown, Western Australia.[2] In a generic revision in 2013, Lars Hendrich and Michael Balke synonymised Allomatus Mouchamps, 1964 with Batrachomatus Clark, 1863, thus changing the species name.[4]