Son of the artist Luke Fildes, Paul Fildes studied surgery at Trinity College, Cambridge, where he obtained an MB BCh degree. Subsequently he was a Surgeon Lieutenant-Commander in the Royal Naval Volunteer Reserve and served in the Royal Naval Hospital Haslar (1915–19). In 1919 he was made an Officer of the Order of the British Empire and in 1946 a Knight Bachelor. He helped Donald D. Woods discover how sulphonamides worked; was a member of the scientific staff, Medical Research Council (1934-49); Fellow of the Royal Society and author of works on haemophilia and syphilis. Fildes received the Copley Medal in 1963.
World War II 
Fildes reportedly asserted that he assisted with Operation Anthropoid, the assassination of top Nazi Reinhard Heydrich in Prague by providing the Czech agents of the Special Operations Executive with modified No. 73 Grenades filled with Botulin toxin.
- Life science essay at U of Pennsylvania
- National Portrait gallery
- Fellow list of the Royal Society