Semaprochilodus is a genus of South American freshwater fish in the family Prochilodontidae. They have sometimes been included in the genus Prochilodus instead. Of the six species, three are from the Amazon Basin, two from the Orinoco Basin and a single from the Maroni Basin. Depending on the exact species, they reach a maximum length of 24–44 centimetres (9.4–17.3 in).