Commander Harold William Swithinbank RNVR (7 March 1858 – 9 February 1928) was a British veterinarian who served in both the army and navy. He was Governor of the Royal Agricultural Society and Vice President of the Royal Veterinary College.
Swithinbank was born in Newcastle-upon-Tyne, Northumberland on 7 March 1858, the second son of George Edwin Swithinbank FSA LLD (b. 1833) and his wife Constantia Anne Briggs.
He trained as a veterinarian but had a largely military career beginning as a Lieutenant in the 11th Hussars, then as a Captain in the Middlesex Yeomanry (Cavalry section).
Swithinbank served as Justice of the Peace for Buckinghamshire and in 1891 was High Sheriff. He lived most of his later life at Denham Court in Denham, Buckinghamshire and was later Deputy Lieutenant of Buckinghamshire.
In 1905, Swithinbank was elected a Fellow of the Royal Society of Edinburgh. His proposers were Sir German Sims Woodhead, George Newman, Diarmid Noel Paton, and Daniel John Cunningham.
In the First World War, he served as a Commander in the Royal Navy Reserve.
Swithinbank died at sea on 9 February 1928 and was buried at sea.