Rhinichthys, known as the riffle daces, is a genus of freshwater fish in the carp family (Cyprinidae) of the order Cypriniformes.

The genus contains eight living species, one of which (the loach minnow) is considered Vulnerable.

The cheat minnow (Pararhinichthys bowersi), a natural hybrid of the longnose dace (R. cataractae) and the river chub (Nocomis micropogon), was formerly placed in this genus, but is now valid under Pararhinichthys.

The riffle daces are a basal lineage in an insufficiently resolved clade of American Leuciscinae.

Such a group had been proposed on anatomical evidence, and was verified using mtDNA 12S rRNA sequences.