Ernst von Rüchel (21 July 1754 – 14 January 1823) was a Prussian general who fought in the army of the Kingdom of Prussia during the French Revolutionary Wars. Afterward he held various appointments as a diplomat and a military inspector. In 1806 during the Napoleonic Wars he held an important army command but was involved in the crushing defeat at the Battle of Jena-Auerstedt. Wounded, he managed to escape the French pursuit, but never commanded troops in combat again.