The Potez 6D is a French six cylinder inverted inline aircraft engine put into production after World War II in normal and supercharged versions.

Unsupercharged, it produced a take-off power of 179 kW (240 hp) at 2,530 rpm.

The Potez 4D, a four-cylinder inverted inline engine ran before World War II but did not reach production until the late 1940s, when it was joined by another inverted inline, the six cylinder 6D, and an eight-cylinder inverted-V, the Potez 8D.

The D-series engines had much in common, most obviously sharing pistons and cylinders, with the same stroke, bore and valve gear.

The inlines also shared connecting rods and lubrication systems and were offered in normally aspirated or supercharged versions.