An image pickup apparatus that suppresses looseness of an accessory fastened to a fastening portion of an apparatus body. An image pickup apparatus includes an accessory that includes a pair of fastening members, and an apparatus body including two fastening portions to which the accessory is removably fastened using the pair of fastening members. The accessory is provided with a second fitting portion which is fitted to one of first fitting portions formed around the fastening portions, by protrusion-recess fitting, in a state in which the accessory is fastened to the fastening portions of the apparatus body using the fastening members. One of the first fitting portion and the second fitting portion is formed by two fitting portions provided in association with the fastening members, and the other is formed by at least one fitting portion.