The focus control apparatus performs focus control of the interchangeable lens by using information obtained through detection of a focus state of an interchangeable lens and a correction value corresponding to the interchangeable lens. The interchangeable lens is a first interchangeable lens holding unique correction value calculation data used to calculate the correction value, or a second interchangeable lens not holding the correction value calculation data. The focus control apparatus includes a first memory storing values for calculating the correction value corresponding to the second interchangeable lens. A controller calculates the correction value by using the correction value calculated based on the values read from the first memory when the second interchangeable lens is attached to the image capturing apparatus, and by using the correction value calculation data acquired from the first interchangeable lens when the first interchangeable lens is attached to the image capturing apparatus.