Stephen Marius Balzer (1864?-1940) was an inventor and early automobile manufacturer. Balzer migrated to the United States in the 1870s. He originally lived in the Bronx, but had moved to Andover New Jersey by the time of his death in 1940. Balzer first apprenticed as a watchmaker at Tiffany's and later set up his own machine shop. He invented and patented a number of devices, including a rotary engine for an automobile and a device for making milling cutters. Balzer set up his own machine shop to try to capitalize on his patents. In the 1890s he built an automobile with a gasoline powered rotary engine and built an aero-engine (that was extensively modified by Charles M. Manly) for Smithsonian Institution Secretary Samuel P. Langley. Balzer died in Andover, New Jersey in 1940.