An electric parking brake system includes an electric parking brake mechanism that includes a brake which suppresses rotation of a wheel and an electric motor which applies or releases the brake, and that maintains a vehicle at a standstill while the brake is applied. A parking switch selectively outputs an application command for applying the brake and a release command for releasing the brake in response to an operation of an operating portion for the parking switch. A parking switch malfunction determination unit determines whether the parking switch malfunctions, and a parking brake automatic control unit automatically applies the brake by operating the electric motor when an ignition switch of the vehicle is turned off in response to an operation of an operating portion for the ignition switch, in a case where the parking switch malfunction determination unit determines that the parking switch malfunctions.