IN-WHEEL MOTOR DRIVE DEVICE

An in-wheel motor drive device () includes a wheel hub bearing unit () having an outer ring () , an inner ring () protruding from the outer ring to one side in an axial (O) direction, rolling elements () between the outer ring and the inner ring, and a fixing bolt () for fixing the outer ring to a non-rotary member (); and a brake disk () having a connecting portion () configured to connect with one end of the inner ring, a cylindrical portion () extending from the connecting portion to the other side in the axial direction and disposed coaxially to the inner ring, and at least a part of the fixing bolt is received in an internal space of the cylindrical portion.