This vehicle body structure comprises: a pair of side members; side sills provided along the vehicle front-rear direction on both sides of a body in the vehicle width direction, and that oppose outer side surfaces of the side members in the vehicle width direction; box-shaped brackets that protrude inward in the vehicle width direction from the inner side surfaces of the side sills in the vehicle width direction, and that oppose the outer side surfaces of the side members in the vehicle width direction; and a side step that is provided on the outside of each of the side sills in the vehicle width direction, and that is supported on the body via a support arm. The support arm extends from the side step towards the inside in the vehicle width direction, and is fixed to the bracket.