The present invention provides a radiation imaging apparatus including an imaging unit including a plurality of pixels and a control unit. Each of the plurality of pixels includes a conversion unit configured to generate an image signal corresponding to incident radiation and a sample/hold circuit configured to hold an image signal generated by the conversion unit. The control unit causes the imaging unit to perform first imaging and second imaging after the first imaging to generate one energy subtraction image, and controls a timing of causing the sample/hold circuit in the first imaging to sample a first image signal obtained by the first imaging and a timing of causing the sample/hold circuit in the second imaging to sample a second image signal obtained by the second imaging in accordance with radiation irradiation conditions set in advance so as to reduce a difference between an amount of noise contained in the first image signal and an amount of noise contained in the second image signal.
