A popular American children's author, he won the 2011 Newbery Medal for his work, Dead End in Norvelt. His most famous characters are a cat named Rotten Ralph and a boy with ADHD named Joey Pigza.
He studied at Emerson College in Boston. He published his first children's book, Rotten Ralph, in 1976.
His 2002 memoir, Hole in My Life, was a finalist for the National Book Award.
He was born in Mount Pleasant, Pennsylvania to Elizabeth Weaver (a banker) and John Gantos (a construction worker).
He was influenced by fellow children's author, Roald Dahl.