Provided is a photoelectric conversion device including: a pixel array including pixels arranged to form columns; and a readout unit including column readout circuits provided corresponding to the columns, each of the column readout circuits being configured to read out signals from the pixels in a corresponding column. Each of the column readout circuits includes a holding unit configured to hold a reference voltage supplied from a reference voltage line, an amplifier unit configured to amplify a signal output from one of the pixels based on the reference voltage held in the holding unit, and a switch unit configured to electrically disconnect the reference voltage line from the holding unit when the amplifier unit amplifies the signal. The holding unit of a first column readout circuit and the holding unit of a second column readout circuit are electrically connected to each other by a path other than the switch unit.