A control device for an internal combustion engine includes an in-cylinder pressure detector, an output shaft torque calculator, a target torque calculator, an input torque parameter calculator, and a controller. The output shaft torque calculator is to calculate an output shaft torque of an output shaft of the internal combustion engine based on an in-cylinder pressure. The target torque calculator is to calculate a target torque of the output shaft torque. The input torque parameter calculator is to calculate an input torque parameter representing an input torque such that the output shaft torque becomes equal to the target torque using a feedback control algorithm which is based on a controlled object model which models a controlled object that receives the input torque parameter as input and produces the output shaft torque as output. The controller is to control the output shaft torque using the input torque parameter.