Carl Eduard Heusner (8 January 1843 – 27 February 1891) was a Vice-Admiral of the German Imperial Navy (Kaiserliche Marine).
In March, von Knorr put him to develop 'Plan-O' for naval operations against Russia in case of war.
His plan called for an attempt at a quick and decisive battle to cripple the Russian fleet, followed by the mining of ports and blockade by a screen of light warships.
In 1888 Wilhelm II appointed him as Chief of the Navy Department (Marineabteilung) in the Admiralty and promoted him to Rear Admiral.
In April 1889 he became Secretary of the German Imperial Naval Office in the Cabinet of Otto von Bismarck.