Herbert Warington Smyth (4 June 1867 – 19 December 1943) CMG, FGS, FRGS, was a British traveller, writer, naval officer and mining engineer who served the government of Siam and held several important posts in the Union of South Africa.
His younger brother Sir Nevill Maskelyne Smyth won the Victoria Cross at the Battle of Omdurman.
He took an active part in World War I as an Acting Sub Lieutenant RNR in 1914, serving as Assistant Naval Transport Officer in the South-West Africa Campaign 1914 to 1915, when he was mentioned in dispatches.
He became Lieutenant RNVR and Acting Naval Senior Officer at the Cape from 1915 to 1916, and Controller of Imports and Exports for the Union of South Africa in 1917.
In 1900 he married Amabel Mary (1879-1965), third daughter of Sir Henry John Sutton KC and his wife Caroline Elizabeth Nanson.