The Ford B series is a bus chassis that was manufactured by the Ford Motor Company. Produced across six generations from 1948 to 1998, the B series was a variant of the medium-duty Ford F series. As a cowled-chassis design, the B series was a bare chassis aft of the firewall, intended for bodywork from a second-stage manufacturer. While primarily used for school bus applications in the United States and Canada, the chassis was exported worldwide to manufacturers to construct bus bodies for various uses.