A photoelectric conversion apparatus includes a plurality of pixels arranged in a matrix, a plurality of signal processing units each corresponding to a column of the matrix, and a signal line. Each of the plurality of signal processing units includes a first capacitance and a second capacitance that hold a signal, a switch provided between the signal line and the first capacitance, a capacitance adjustment unit electrically connected to the second capacitance, and a connection unit configured to electrically connect the first capacitance provided to one of signal processing units to the second capacitance provided to another one of the signal processing units.