Between 1920 and 1951 the Société des Moteurs Salmson in France developed and built a series of widely used air-cooled aircraft engines.

[1] After their successful water-cooled radial engines, developed from 1908 to 1918, Salmson changed their focus to air-cooling to reduce weight and increase specific power (power per unit weight).

In common with other engines produced by this manufacturer, the air-cooled radial engines featured the unorthodox Canton-Unné internal arrangement that dispensed with a master rod in favour of a cage of epicyclic gears driving the crankpin.

Production ended in 1951 with the liquidation of the manufacturing company.

In common with several other French aero-engine manufacturers Salmson named their engines with the number of cylinders then a series letter in capitals followed by variant letters in lower-case.