Nothonotus is a genus or subgenus of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. It is endemic to the southeastern United States. First proposed as a sub-genus of Etheostoma in 1988, there is still debate regarding the appropriate taxonomic rank of Nothonotus in the literature . Darter species comprise more than 180 of the Percidae taxa.