In a rear wheel support structure for a motorcycle or a three-wheeled vehicle in which a proximal end portion of a swing arm is vertically tiltably supported on a vehicle body frame by way of a tilting support shaft, a rear wheel is rotatably supported on the swing arm by way of a rear axle, and a rear shock absorber is interposed between the swing arm and the vehicle body frame. The comfort of the ride is enhanced by ensuring a sufficiently long effective stroke of the rear shock absorber with respect to a stroke of the rear wheel. A tilting support shaft of a swing arm is arranged behind a rear axle in the longitudinal direction of the vehicle.