The Monti Ausoni or Ausoni Mountains is a mountain range in southern Lazio, in central Italy. It is part of the Antiappennini, a group running from the Apennines chain to the Tyrrhenian Sea. They are bounded to the north by the Monti Lepini and to the south by the Monti Aurunci.
They take the name from the ancient tribe of the Ausoni.
The Monti Ausoni consist mainly of friable limestone. Altitudes vary from hills to the 1,152 m of Cima del Nibbio and the 1141 m of Monte Calvo. Near Pastena are the eponymous Grotte (caves).