A radiation imaging system includes a housing containing a plurality of radiation imaging devices each including a radiation detecting panel having a two-dimensional matrix of pixels and arranged to convert applied radiation to an image signal, a plurality of retainers configured to position and retain the plurality of radiation imaging devices so that parts of the respective radiation imaging devices spatially overlap as viewed from an irradiation side, and a unit configured to acquire a radiographic image on the basis of image signals from the respective radiation imaging devices. The plurality of retainers are configured to retain the plurality of radiation imaging devices in areas other than effective pixel areas of the respective radiation imaging devices.
