Ernst Wilhelm Eduard von Knorr (8 March 1840 – 17 February 1920) was a German admiral of the Kaiserliche Marine who helped establish the German colonial empire.
Born in Saarlouis, Rhenish Prussia, Knorr entered the Prussian Navy in 1856. While serving on the corvette Danzig, he fought against pirates off the coast of Morocco later that year. In 1859 he was promoted to Unterleutnant. From 1859–62 he sailed with the Elbe on an expedition to the Far East. Knorr was promoted to Leutnant in 1862 and Kapitänleutnant in 1865.
On 12 November 1870, during the Franco-Prussian War, Knorr commanded the gunboat Meteor in a battle with the French aviso Bouvet near Havana, for which he was awarded the Iron Cross 2nd Class. In 1871 he was promoted to Korvettenkapitän.
Beginning in 1874, Knorr took part in a voyage through the Pacific Ocean to discuss trade negotiations with Tonga on behalf of the German Empire. He was named Kapitän zur See in 1876, Chief of Staff of the Admiralty in 1881, and Konteradmiral in 1883.
As commander of the West African Squadron in December 1884, Knorr intervened in disputes between rival clans in Douala, Cameroon, imposing German sovereignty over the Cameroon Estuary. He was awarded the Order of the Red Eagle for this success. From 1 April 1885 – 4 July 1885 Knorr was Reichskommissar of the German colony of Kamerun. He then commanded a cruiser squadron travelling to Zanzibar and negotiated with its sultan for the acquisition of a strip of German colonial territory.
In 1886 Knorr commanded a cruiser squadron at Samoa. He was promoted to Vizeadmiral in 1889, Admiral in 1893, and Commanding Admiral in 1895. Raised to the German nobility on 18 January 1896, he received the Order of the Black Eagle on 15 June 1898. Knorr retired in 1899 and was appointed an admiral à la suite of the Seeoffizierkorps.
Knorr died in Berlin. Admiral-Knorr-Straße, a street in Saarlouis, is named after him.