William Davies (sometimes credited as William Davis or Will Davies) is an English screenwriter and producer. He has written and co-written several films, including Twins (1988), The Real McCoy (1993), the Johnny English franchise (2003-2018), Alien Autopsy (2006), Flushed Away(2006), How to Train Your Dragon (2010), Puss in Boots (2011), and Lyle, Lyle, Crocodile (2022).

The British-born Davies is a graduate of Mercersburg Academy and Cambridge University. He is the brother of television producer Michael Davies and the opera singer Rebecca de Pont Davies.