A focus detection apparatus includes: a photoelectric conversion unit of a charge accumulation type, including a plurality of sensors; an accumulation controller for controlling charge accumulation of the photoelectric conversion unit; an accumulation time measuring unit for measuring accumulation time; a correction computing unit for performing correction computing of a photoelectric conversion signal; and a focus detection computing unit for performing focus detection computing. The accumulation controller detects a signal of accumulation completion in a first sensor of the plurality of sensors, and then forces sensors except the first sensor to terminate the charge accumulation. The correction computing unit performs the correction computing of the photoelectric conversion signal based on first accumulation time that is accumulation time of the first sensor and second accumulation time that is different from the first accumulation time.