Provided is an internal-combustion-engine control device that minimizes a detection error of a cylinder pressure sensor used in a control of an internal combustion engine. The internal-combustion-engine control device is an electronic control unit (ECU) 1 for an internal combustion engine 100 that includes a cylinder pressure sensor 140 for detecting cylinder pressure in a combustion chamber. The ECU 1 includes an overall controller 81 configured to correct an output signal S2 transmitted from the cylinder pressure sensor 140 in a cylinder 150. The overall controller 81 corrects the output signal S2 from the cylinder pressure sensor 140 in accordance with a correction period calculated based on drive of components of the internal combustion engine 100, such as a fuel injector 400.