An imaging element includes: a plurality of pixel units configured to each include a plurality of light receiving elements performing photoelectric conversion; a plurality of analog-to-digital (A/D) converters configured to be provided to each of the pixel units for sequentially converting an analog signal obtained by photoelectric conversion performed by the light receiving elements to a digital signal; a plurality of first holding units configured to be provided to each of the pixel units for sequentially holding a digital signal obtained by conversion performed by the A/D converters; and a plurality of second holding units configured to receive and hold a digital signal held by the first holding units in a period when the A/D converters do not convert an analog signal to a digital signal.