Sous lieutenant Émile Julien Mathurin Régnier (29 July 1894 – 4 September 1940) was a World War I flying ace credited with six aerial victories.

Régnier's death did not close down his aircraft engine company, which subsequently was captured and used by the Nazis during World War II.

In the early days of World War I, on 1 September 1914, he joined the 115th Infantry Regiment of the French Army.

[1] By war's end, Régnier had flown 615 combat hours, fought in 26 dogfights, and carried out 82 special missions.

[4] Régnier designed an inverted air-cooled six-cylinder engine for use in a privately entered Caudron C.366 to compete in the Coupe Deutsch de Meurthe air race in 1934.

[5] On 6 January 1934, one of his engines, mounted in a Caudron C.362, set a new 1,000-kilometer speed record of 332.8 km/h for light aircraft; this was six days too late to claim a 50,000-franc prize from the French air ministry.

[7] The Régnier engine powered a Percival Mew Gull to victory in the Coupe Armand Esders in July 1935 at 302 km/h.

[10] During World War II, the Régnier Motor Company fell into the hands of the invading Nazis, and became a supplier of the German military.