Stephen Richard Lyster Clark (born 30 October 1945) is an English philosopher and professor emeritus of philosophy at the University of Liverpool. Clark specialises in the philosophy of religion and animal rights, writing from a philosophical position that might broadly be described as Christian Platonist. He is the author of twenty books, including The Moral Status of Animals (1977), The Nature of the Beast (1982), Animals and Their Moral Standing (1997), G.K. Chesterton (2006), Philosophical Futures (2011), and Ancient Mediterranean Philosophy (2012), as well as 77 scholarly articles, and chapters in another 109 books. He is a former editor-in-chief of the Journal of Applied Philosophy (1990–2001).