Max Clemens Lothar Freiherr von Hausen (December 17, 1846 – March 19, 1922) was a German military officer during the First World War.

At the beginning of the First World War, he was the head of the Third Army which he led during the Battles of the Frontiers, Charleroi, and the Marne.

Being promoted to Seconde-Lieutenant in 1864 he joined the 3rd Jäger Battalion and served against Prussia in the Austro-Prussian War of 1866; where he saw action at the Battle of Königgrätz.

From 1871 to 1874 Hausen taught at the Prussian military academy in Berlin and from 1875 until 1887 he served on the Imperial German General Staff.

After the stabilization of the front on the Aisne River, on September 9, 1914, Hausen was relieved of his command due to illness and replaced by General Karl von Einem.