A vehicle lower body structure includes: a rocker provided at an outer side, in a vehicle width direction, of a vehicle lower body, the rocker extending in a vehicle front-rear direction; and a floor panel extending in the vehicle width direction and in the vehicle front-rear direction and configuring a floor of a cabin, an end portion, in the vehicle width direction, of the floor panel being mechanically fastened by fasteners to an upper end portion of the rocker in a state in which the end portion of the floor panel overlaps with the upper end portion of the rocker.