The Le Rhône 9C is a nine-cylinder rotary aircraft engine produced in France by Gnome et Rhône. Also known as the Le Rhône 80 hp in a reference to its nominal power rating, the engine was fitted to a number of military aircraft types of the First World War. Le Rhône 9C engines were also produced under license in Great Britain by several companies, and in the United States.
Examples of Le Rhône 9C engines are on view in aviation museums either installed in aircraft exhibits or as stand-alone displays. A few examples of the 9C engine remain airworthy both in Europe and North America, one powering a vintage Sopwith Pupbiplane in England, and a small number of others having powered reproduction WW I-era aircraft at Old Rhinebeck Aerodrome and other American "living' aviation museums that fly their restored, airworthy aircraft.