William of Hesse-Philippsthal-Barchfeld (3 October 1831 – 17 January 1890), was a German prince member of the House of Hesse in the Philippsthal-Barchfeld branch and Konteradmiral (counter admiral) of the Prussian and Imperial German Navy.
Born in Burgsteinfurt, he was the fourth son of Charles, Landgrave of Hesse-Philippsthal-Barchfeld and his second wife Sophie, daughter of Prince Louis William Geldricus Ernest of Bentheim and Steinfurt.
After serving as cadet and watch officer in the Royal Danish Navy and the British Royal Navy, William joined the Prussian Navy on 29 January 1854 as Lieutenant 1st Class, (captain lieutenant). In the summer of 1854 he served as commanding officer of the corvette Amazone. On 15 October 1854 he was promoted to the rank of Korvettenkapitän (corvette captain). In the winter of 1855/56, he served as Director of the 2nd Division of the Admiralty.
At the same time he took command of the corvette Danzig, a post which he held until November 1856. In this ship he participated in an expedition under the command of Admiral Prince Adalbert to Africa. During the trip, William came into conflict with the Admiral for his punitive actions against the Riffians. Adalbert released William from active service for about a month until the Battle of Tres Forcas on 7 August 1856. After returning home was William was again released from active duty from November 1856 to April 1859. During this time, he was promoted to the rank of Kapitän zur See (captain at sea) on 24 October 1857.