Louis Ernest of Brunswick-Lüneburg-Bevern (25 September 1718, Wolfenbüttel – 12 May 1788, Eisenach) was a field-marshal in the armies of the Holy Roman Empire and the Dutch Republic. From 13 November 1750 to 1766 he was the Captain-General of the Netherlands, where he was known as the Duke of Brunswick or (to distinguish him from his eldest brother Charles, who succeeded to their father's title of Duke of Brunswick-Lüneburg) Duke of Brunswick-Wolfenbüttel. Another brother was Duke Ferdinand of Brunswick who led the Allied Anglo-German army during the Seven Years' War.