Coihueco (Spanish pronunciation: [kojˈweko]) is a Chilean commune and city in Punilla Province, Ñuble Region.

According to the 2002 census of the National Statistics Institute, Coihueco spans an area of 1,776.6 km2 (686 sq mi) and has 23,583 inhabitants (12,211 men and 11,372 women).

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

[1][2] Within the electoral divisions of Chile, Coihueco is represented in the Chamber of Deputies by Carlos Abel Jarpa (PRSD) and Rosauro Martínez (RN) as part of the 41st electoral district, together with Chillán, Pinto, San Ignacio, El Carmen, Pemuco, Yungay and Chillán Viejo.

The commune is represented in the Senate by Victor Pérez Varela (UDI) and Mariano Ruiz-Esquide Jara (PDC) as part of the 13th senatorial constituency (Biobío-Coast).