A differential device includes a ring gear receiving a rotational driving force from a drive gear, a differential case rotating integrally with the ring gear around a predetermined axis, and a differential mechanism installed within a barrel part of the differential case. The ring gear includes a gear portion meshing with the drive gear, and a rim portion that is formed integrally with an inner periphery of the gear portion and is fitted, in a non-welded state, onto a maximum diameter outer peripheral portion of the barrel part or a predetermined outer peripheral portion having a smaller diameter than the maximum diameter outer peripheral portion. The rim portion has a to-be-fixed portion welded to the barrel part at a position spaced in an axial direction from a fitting part via which the rim portion and the barrel part are fitted, the position being further radially inward than the fitting part.