Simon was born in Chichester in 1988 and has lived there ever since. After studying History at Exeter University, he decided to become a primary school teacher. Teaching rekindled his love of children's books, so much so that he decided to have a go at writing his own. He is the author of I Don't Know What to Call my Cat, You Must Bring a Hat, and the I Really Want series: I Really Want the Cake (2017) shortlisted for the Waterstones Children's Book Prize, I Really Want to Win (2019), I Really Want to Shout (2020) and I Really Want to Share (2022).