Wallace Brian Vaughan Sinclair (27 September 1915 – 13 December 1988) was a British veterinary surgeon who worked for a time with his older brother Donald Sinclair and Donald's partner Alf Wight. Wight wrote a series of semi-autobiographical books under the pen name James Herriot, with Brian and Donald Sinclair appearing in fictionalised form as brothers Tristan and Siegfried Farnon.