Oskar Philipp von Chelius (1859–1923) was a Prussian Generalleutnant who served during World War I as an Adjutant of Emperor Wilhelm II and as a military attaché.

Oskar von Chelius was born on 28 July 1859 at Mannheim, which was part of the Grand Duchy of Baden.

[1] In 1881, Chelius entered the Imperial German Army as a Fahnenjunker in the 22nd (3rd Baden) Dragoon Regiment.

In 1883, Chelius was transferred to the Life Guards Hussars in Potsdam and later became the regimental adjutant.

During military maneuvers in Mark Brandenburg, Chelius and Wilhelm II met and became a great friends.

In 1895 he served on the staff of the Guards Corps, commanded by Hugo von Winterfeld.