A distance measurement apparatus includes an imaging lens configured to form an image of an object on an imaging plane, a solid-state image sensor configured to acquire an image based on light flux passing through a plurality of areas different from each other in an exit pupil of the imaging lens, and a calculation unit configured to calculate a distance based on a signal acquired from the solid-state image sensor. The calculation unit includes a processing unit configured to acquire a first signal in a first imaging condition by using the solid-state image sensor, a processing unit configured to acquire a second signal in a second imaging condition different from the first imaging condition by using the solid-state image sensor, and a processing unit configured to calculate a base length and a distance based on the first signal and the second signal.