An in-wheel motor drive assembly (11) includes a motor unit that drivingly rotates a motor-side rotating member, a speed reduction unit that reduces the rotational speed of the motor-side rotating member and transmits the reduced rotation to a wheel-side rotating member, a wheel hub (26) that is fixedly coupled to the wheel-side rotating member, a wheel hub bearing that rotatably supports the wheel hub (26), a casing (12) that covers the motor unit, the speed reduction unit, and the wheel hub bearing, a plurality of sensors (43) that are mounted on the casing (12) and capable of detecting strain generated in the casing (12), and a signal processor (46) that calculates load imposed on a wheel on the basis of strain signals output from the sensors (43).