The longnose sucker (Catostomus catostomus) is a species of freshwater fish in the Catostomidae Family of Order Cypriniformes. It is native to North America from the northern United States to the top of the continent. It is also found in Russia in rivers of eastern Siberia, making it one of only two species of sucker native to Asia (the other is the Chinese Myxocyprinus asiaticus).