The Clerget 9B was a French nine-cylinder aircraft engine of the Great War era designed by Pierre Clerget, a French engineer and inventor. It was manufactured in both France and Great Britain by Clerget-Blin and Gwynnes Limited, respectively. The Clerget 9B was used on several aircraft models, such as the Sopwith Camel, the Sopwith Triplane, and the Fairey Hamble Baby. It had a power output of 130 hp (97 kW) at 1,250 rpm and a displacement of 16.29 L (994.08 cu in). These engines had a simple and reliable design, with one intake and one exhaust valve per cylinder, two magnetos for ignition, and a carburettor or fuel injection system for fuel delivery. It also had a throttle, which allowed the pilot to control the engine speed more precisely than other rotary engines of the time. The Clerget 9B was one of the most successful rotary engines of the war, but it also had some drawbacks, such as high fuel and oil consumption, overheating, and short lifespan of some components.