Sacco
The river’s valley seen from the Acropolis of Alatri
Origin	Colle Cero, Monti Simbruini
Mouth	Liri, near Ceprano
Basin countries	Italy
Length	87 km
Avg. discharge	16 m³/s

The Sacco is a river of central Italy, a right tributary of the Liri.

The river is formed by the confluence of two streams of the Monti Simbruini in the Apennines of Abruzzo. It flows towards south-east for a total of 87 km, crossing Ciociaria between the mountain ranges of the Ernici to the north-east, and of the Lepini to the south-west. It flows into the Liri near Ceprano, in the Lazio.

The Sacco's main tributaries are the Cosa and the Alabro.

In the Frosinone area it is known also the Tolero, from its ancient name Tolerus or Trerus.

Coordinates: 41°31′N 13°32′E / 41.517°N 13.533°E / 41.517; 13.533