A photoelectric conversion device includes a pixel region in which pixels are arranged to form rows and columns, control lines each connected to the pixels on a corresponding row, output lines connected to the pixels on a corresponding column, a pixel control unit configured to supply control signals to control the pixels for the control lines, and a signal processing unit configured to select and output a signal output to the output lines. The pixel region includes readout regions each including a block of the pixels arranged on continuous rows and columns, and at least one row includes both of the pixel of the block forming a first readout region and the pixel of the block forming a second readout region. The pixel control unit and the signal processing unit are configured to read out signals of the pixels in a corresponding block sequentially for each of the readout regions.