Within the electoral divisions of Chile, Petorca is represented in the Chamber of Deputies by Eduardo Cerda (PDC) and Andrea Molina (UDI) as part of the 10th electoral district, (together with La Ligua Cabildo, Papudo, Zapallar, Puchuncaví, Quintero, Nogales, Calera, La Cruz, Quillota and Hijuelas). The commune is represented in the Senate by Ignacio Walker Prieto (PDC) and Lily Pérez San Martín (RN) as part of the 5th senatorial constituency (Valparaíso-Cordillera).
