William "Bill" Denbrough is a fictional character created by Stephen King and the main protagonist of his 1986 novel It. The character is considered to be the leader of "The Losers Club" and initiates finding and killing Pennywise after it kills his younger brother Georgie. The character was first portrayed in the 1990 TV mini-series by Jonathan Brandis as a child, and by Richard Thomas as an adult. In the 2017 adaptation and its 2019 sequel, the character was portrayed by Jaeden Martell as a child and James McAvoy as an adult.