The Hernici were an Italic tribe of ancient Italy, whose territory was in Latium between the Fucine Lake and the Sacco River (Trerus), bounded by the Volsci on the south, and by the Aequi and the Marsi on the north.
For many years of the early Roman republic they were allied with Rome and fought alongside it against its neighbours.
In 475 BC they fought alongside the Latins against the Aequi and Volsci, and in the same year fought alongside Rome against the Veientes and Sabines. In 468 BC they fought alongside Rome against the Volsci.
They broke away from Rome in 362 and in 306, when their chief town Anagnia was taken and reduced to a praefectura, but Ferentinum, Aletrium and Verulae were rewarded for their fidelity by being allowed to remain free municipia, a position which at that date they preferred to the civitas.
The name of the Hernici, like that of the Volsci, is missing from the list of Italian peoples whom Polybius describes as able to furnish troops in 225 BC; by that date, therefore, their territory cannot have been distinguished from Latium generally, and it seems probable that they had then received the full Roman citizenship. The oldest Latin inscriptions of the district (from Ferentinum) are earlier than the Social War, and present no local characteristic.