I saw the name in the CNN documentary The Radical Story of Patty Hearst. Jolyon was, I believe, a lawyer on the case. Note that others he worked with sometimes called him “Joly” pronounced Jolly as in gregarious, happy. Not exactly ‘famous’ but it’s how I found this interesting name.
A famous bearer is British racing driver Jolyon Palmer.
― Anonymous User 4/4/2017
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In the novel "Endymion Spring," by Matthew Skelton, Professor Jolyon Fall at Oxford University befriends one of the main characters, Blake, and his sister, Duck (not her real name of course).