An in-wheel drive unit capable of decreasing the axial length and the outer diameter of the whole unit. This in-wheel drive unit is composed of a motor (1), a planetary reduction gear (2), an output shaft (3) and a wheel rim (4). At least one of bearings (5, 6) for rotatably supporting a rotating element of the planetary reduction gear (2) drivingly connected to the output shaft (3) is positioned widthwise inward more than the widthwise central surface (EX) of the wheel rim (4). The output shaft is rotatably supported by the bearings (5, 6). |