A supplemental turning function-equipped hub unit includes: a hub unit body including a hub bearing; and a unit support member configured to be mounted through a suspension device, the unit support member supporting the hub unit body through rotation-permitting support components at two upper and lower portions of the hub unit body such that the hub unit body is rotatable about a supplemental turning axis. A supplemental turning force receiving part is provided on a side part of the hub unit body, which part is configured to receive a force that causes the hub unit body to rotate about the supplemental turning axis.