11C, 11-C or 11.C may refer to:
New York State Route 11C GCR Class 11C, a class of British 4-4-0 steam locomotive 11C, a U.S. Army MOS for a mortarman The clockwise bus service on West Midlands bus route 11 Carbon-11 (11C), an isotope of carbon
See also Secondary State Highway 11C (disambiguation) C11 (disambiguation)