A radiation imaging apparatus in which a pixel for obtaining an image based on radiation and a light shielded pixel which is shielded from light are arranged in an array, comprises: a setting unit configured to set a region including a plurality of pixels for obtaining the image based on the radiation and cause pixel values based on the plurality of pixels in the region to be output; and a correction unit configured to determine whether the light shielded pixel is included in the region, and correct the pixel values based on the plurality of pixels in the region if the light shielded pixel is included in the region.