To maintain smooth rotation of a pinion gear, a differential device includes: a differential case including a case main body and a bearing boss protruding from the case main body and rotatably supported about a first rotation axis; a side gear; and a pinion gear. An introduction groove for introducing lubricating oil into the case main body is formed on the bearing boss. An inner surface groove communicating with the introduction groove and extending toward the pinion gear is formed on the case main body. The inner surface groove includes a first groove portion and a second groove portion positioned radially outward from the first groove portion in the radial direction. The shape of at least a part of the first groove portion is a shape over which the lubricating oil is hard to climb during vehicle forward movement as compared with the shape of the second groove portion.