In a photoelectric conversion apparatus, an amplification unit outputs a first amplified signal generated by amplifying a first signal using a first gain, a second amplified signal generated by amplifying the first signal using a second gain, a third amplified signal generated by amplifying a second signal using a third gain, and a fourth amplified signal generated by amplifying the second signal using a fourth gain to an analog to digital (AD) conversion unit in this order. The AD conversion unit generates first to fourth digital signals corresponding to the first to fourth amplified signals, respectively, and outputs the second digital signal and the third digital signal to an output unit prior to the first digital signal and the fourth digital signal.