John Backderf, also known as Derf or Derf Backderf, is an American cartoonist. He is most famous for his graphic novels, especially My Friend Dahmer, the international bestseller which won an Angoulême Prize, and earlier for his comic strip The City, which appeared in a number of alternative newspapers from 1990 to 2014. In 2006 Derf won the Robert F. Kennedy Journalism Award for cartooning. Backderf has been based in Cleveland, Ohio, for much of his career.

My Friend Dahmer is a 2012 graphic novel and memoir by artist John "Derf" Backderf about his teenage friendship with Jeffrey Dahmer, who later became a serial killer. The book evolved from a 24-page, self-published version by Backderf in 2002.