Vehicle body floor structure includes a floor frame of an upwardly-opening U sectional shape extending in a length direction of a vehicle centrally on a floor panel provided in a floor section of a vehicle compartment, and a collective piping bracket provided under the floor panel between a flange of the floor frame and an outer surface of the floor panel. The collective piping bracket is fixedly joined to the flange of the floor frame in spaced-apart relation to the floor panel.