A photoelectric conversion device comprising: a plurality of effective pixels and a plurality of light shielded pixels which are arranged respectively in a plurality of rows and a plurality of columns; and a signal processing circuit, wherein in a period during which pixel signals are output from first light shielded pixels which are first-row light shielded pixels to a first vertical output line, pixel signals are output from second light shielded pixels which are second-row light shielded pixels to a second vertical output line, and the signal processing circuit corrects effective pixel signals output from the effective pixels by using a correction signal obtained by performing filtering processing on pixel signals from the first light shielded pixels and on the pixel signals from the second light shielded pixels.