A photoelectric conversion device includes a pixel array including a plurality of pixels arranged in a matrix, and a plurality of signal processing units each associated with a respective one of columns of the pixel array and including an A/D conversion unit configured to convert a signal generated based on the pixels into a digital signal. The photoelectric conversion device further includes a plurality of groups each including a plural ones of signal processing units out of the plurality of signal processing units and a block output unit configured to receive outputs of the plural ones of signal processing units, and a driving signal transmission unit configured to transmit a driving signal for driving a plurality of the block output units. The driving signal transmission unit supplies, to one of the block output units and another of the block output units, the driving signal at respective different timings.