An engine system includes an engine that, a fuel supply device, and an electronic control unit. The electronic control unit is configured to control the fuel supply device and to perform operation control of the engine by adjusting an injection ratio between fuel injection from an in-cylinder injection valve and a port injection valve according to the operation state of the engine. The electronic control unit is configured to perform imbalance determination. The electronic control unit is configured to change a region of fuel injection from a first fuel injection region to a second fuel injection region when the electronic control unit determines that a lean imbalance is occurred with respect to the fuel injection in which the fuel injection from the port injection valve is performed.