Oisín McGann (born Dublin, 1973) is a children's and young adult author and illustrator, and a former animator and comics artist. Educated at Ballyfermot College and Dun Laoghaire School of Art and Design, he worked as a freelance illustrator, animation artist and advertising illustrator and copywriter during the 1990s. During this period he also drew comics for Twisted.
His first two children's books, Mad Grandad's Flying Saucer and Mad Grandad's Robot Garden, was published in 2003. As well as five more books in the Mad Grandad series, he has written three Forbidden Files books for older children, and nine novels for young adults, beginning with The Gods and Their Machines in 2004.