Leutnant Olivier Freiherr von Beaulieu-Marconnay (14 September 1898 – 26 October 1918) was a German World War I ace fighter pilot credited with 25 victories.

[1][2] Olivier Freiherr (Baron) von Beaulieu-Marconnay was born in Charlottenburg on 14 September 1898, the son of an aristocratic Prussian Army captain.

[2] However, he developed such a close friendship with two other teenage aces, Georg von Hantelmann and Hugo Schäfer, that they were dubbed The Inseparables.

[3] Jagdstaffel 15 had recently received the new Siemens-Schuckert D.III fighters, and were limited to defensive operations, as they had orders forbidding flights over enemy lines lest one of the new planes fall into Allied hands.

[1][2] On 18 October, in the confusion of a dogfight, Beaulieu-Marconnay was seriously wounded in the thigh, possibly as a result of friendly fire from a fellow German pilot[2] from Jagdstaffel 74.

However, Olivier Freiherr von Beaulieu-Marconnay, who had lingered with his wound for eight days, died six hours before the news arrived, possibly as the result of a post-operative infection.