Wilhelm Reichsfreiherr[1] von Innhausen und Knyphausen [notes 1] (4 November 1716 Lütetsburg, East Frisia – 7 December 1800 Kassel) was a German general officer who served in Hesse-Kassel.

Educated in Berlin, the young Knyphausen entered the Prussian military service in 1734, and in 1775 he became a general officer in the army of Frederick the Great.

In 1776, with 42 years of military experience, he came to the Thirteen Colonies of British North America as second-in-command of an army of 12,000 men called "Hessians" under General Heister.

[2] Knyphausen led the Hessian troops in the Battles of White Plains, Fort Washington, Brandywine, Germantown, Springfield, and Monmouth.

For several years the main body of Knyphausen's force occupied the upper part of Manhattan Island, and during the temporary absence of Sir Henry Clinton in 1780, he was in command of the city.

Knyphausen left the North American theater in 1782 in part because of ill health, including blindness in one eye caused by a cataract.