A signal processing apparatus that processes image data output from a photoelectric conversion unit including a light-receiving region and a light-blocking region. The apparatus includes a control data generation unit that outputs control data used to generate correction data for correcting the image data using a trained model generated through machine learning, and a signal processing unit that generates the correction data on the basis of light-blocked image data and the control data, the light-blocked image data being image data, among the image data, that is from the light-blocking region, and corrects light-received image data in accordance with the correction data without applying the trained model, the light-received image data being image data, among the image data, that is from the light-receiving region.