The Prong-billed Barbet Semnornis frantzii is a distinctive Neotropical bird.

It often has been united with the other barbets in the Capitonidae. However, DNA studies have confirmed that this arrangement is paraphyletic (the toucans are more closely related to the New World Barbets than the latter are to barbets of the Old World). As a result, the barbet lineages are again considered distinct families ; the Prong-billed Barbet and the Toucan Barbet now form a separate family, Semnornithidae.

The binomial commemorates the German naturalist Alexander von Frantzius.