Major-General Sir Harold Augustus Wernher, 3rd Baronet, GCVO, TD (16 January 1893 – 30 June 1973) was a British military officer and diamond magnate.

He reached the rank of major-general during World War II, and he played an important role in coordinating the logistics of Operation Overlord.

In September 1943, Sir Harold was appointed by Prime Minister Winston Churchill as Co-Ordinator of Ministry and Science Facilities (CMSF), in charge of overseeing the construction of all the Mulberry Harbour components.

[2] On 20 July 1917, Wernher married Countess Anastasia Mikhailovna de Torby, the eldest child of Grand Duke Michael Mikhailovich of Russia and his morganatic wife, Countess Sophie Nikolaievna of Merenberg, first in a Russian Orthodox ceremony in the chapel of the Russian Embassy in Welbeck Street then in an Anglican ceremony in the Chapel Royal at St James's Palace attended by King George V and Queen Mary.

[3] They had three children: His descendants include the 7th Duke of Westminster and the heirs apparent to the dukedom of Abercorn and the earldom of Dalhousie.