A distance detecting device includes a distance calculation unit configured to calculate a distance to a target of imaging based on a first signal corresponding to a luminous flux having passed through a first pupil region of an exit pupil in an imaging optical system, and a second signal corresponding to a luminous flux having passed through a second pupil region different from the first pupil region, and a signal processing unit configured to perform a filtering process on at least one of the first signal and the second signal by using a band pass filter having a lower number of cells in a first direction than a number of cells in a second direction perpendicular to the first direction, and a filter for phase correction having a higher number of cells in the first direction than the number of cells in the second direction.