A radiation imaging apparatus, comprising a sensor panel in which a plurality of sensors configured to detect radiation are arrayed, a first circuit board that is arranged on the sensor panel and includes a circuit configured to read out a signal from each sensor, and a second circuit board that is arranged on the first circuit board and includes a circuit configured to read out a signal from each sensor, and whose radiant noise generation amount at a driving time of the circuit is larger than a radiant noise generation amount at a driving time of the circuit of the first circuit board, wherein the first circuit board is arranged between the sensor panel and the second circuit board.