A bicycle drive unit is basically provided with an assist motor and a housing such that the distance between a crankshaft and a rear end of the housing is prevented from becoming long. The assist motor is configured to apply an assisting force to a manual drive force, which is inputted from a crankshaft. The housing is provided to the assist motor and at least a part of the crankshaft. The housing is disposed around the crankshaft. The housing is formed so that, when the bicycle drive unit is attached to a bicycle frame, the minimum distance from a center axis of the crankshaft and the rear end surface of the frame on the rear end side of the housing is equal to or less than 50 mm and greater than the radius of the crankshaft, as viewed from parallel to the center axis of the crankshaft.