The Little Colorado River Sucker or Little Colorado sucker ("Catostomus sp.3") is a scientifically undescribed species of North American freshwater fish very similar to the flannelmouth sucker (Catostomus latipinnis) but without the flannelmouth's distinct fleshy lips. The Little Colorado sucker is native to the upper region of the Little Colorado River in Arizona, but was also introduced into the Salt River.