The Monti della Tolfa (or Tolfa Mountains) are a volcanic group in the Anti-Apennines of the northern part of the Lazio region of Central Italy. They are bounded by the Tyrrhenian Sea coast to the west, by the Monti Sabatini to the east, and by the Monti Cimini and the Mignone river to the north. Tolfa and Allumiere are the principal towns.
The highest peak is the Monte Maggiore (633 m above sea level). The Monti della Tolfa consists mostly of trachytes formed during the Eocene and the early Pleistocene.