Simon Farnaby (born 2 April 1973) is an English actor, comedian, children's entertainer, writer and singer. He is best known for his work with the Them There collective, where he has written and starred in productions including the sketch show Horrible Histories, Yonderland, and Ghosts, as well as writing for film.

Farnaby earned BAFTA nominations for his co-writing of Paddington 2, both for Best Adapted Screenplay and Best British Film, and was the winner of the 2023 Television BAFTA for memorable TV moment. In 2023, he co-wrote and appeared in Wonka, a film which serves as a prequel to the Roald Dahl novel Charlie and the Chocolate Factory, exploring Willy Wonka's origins.