The light alloys, such as aluminum and magnesium, have considerable potential for use in the automotive industry. However, the superplastic forming of conventional alloys, where the grain sizes are often ∼5 μm or larger, tends to occur at strain rates which are generally too slow for use in the processing of high volumes of components for use in the fabrication of automobiles or consumer products. This limitation may be removed, and the superplastic forming operation achieved at a faster rate, by reducing the grain size of the alloy to the submicrometer or even the nanometer level. This paper describes the process of achieving grain refinement and superplastic properties in representative Al and Mg alloys using a procedure in which the alloys are subjected to severe plastic deformation. The results show that this processing technique is capable of producing excellent superplastic properties in alloys that are nominally not superplastic.