Admiral Robert Hamilton Anstruther (Chinese: 安史導; 10 June 1862 - 26 September 1938) was the son of Lieutenant-Colonel Sir Robert Anstruther of Balcaskie, 5th Bt. and Louisa Maria Chowne Marshall. He married Edith Flora Peel on 6 January 1890. Their son, Colonel Philip Noel Anstruther, was born on 2 September 1891.
He was Senior Naval Officer of the Danube between 1900 and 1902. He was Senior Naval Officer of the North Sea Fisheries between 1902 and 1904. He was Senior Naval Officer of the Newfoundland Fisheries between 1906 and 1908. He was invested as a Companion, Order of St. Michael and St. George (C.M.G.) in 1907. He was Commander of the Hong Kong in 1912. He was Senior Officer of the coast of China between 1914 and 1916.
He was the second Colony Commissioner of the Boy Scout Association, Hong Kong Branch as of May 1915.