According to the 2002 census of the National Statistics Institute, San Vicente spans an area of 475.8 km2 (184 sq mi) and had 40,253 inhabitants (20,095 men and 20,158 women).

[3] As a commune, San Vicente is a third-level administrative division administered by a municipal council, headed by an alcalde who is directly elected every four years.

Within the electoral divisions of Chile, San Vicente is represented in the Chamber of Deputies by Alejandra Sepúlveda (PRI) and Javier Macaya (UDI) as part of the 34th electoral district, together with San Fernando, Chimbarongo, Peumo, Pichidegua and Las Cabras.

The commune is represented in the Senate by Andrés Chadwick Piñera (UDI) and Juan Pablo Letelier Morel (PS) as part of the 9th senatorial constituency (O'Higgins Region).

Tagua-Tagua represents a very early Paleo-Indian archaeological site, and it is dated to 11,380 ±380 14C yr BP (before present).