Malachy Doyle was born in Carrickfergus, Northern Ireland in 1954, and was named after a local saint. After obtaining an honours degree in Psychology Malachy taught, and worked in advertising before moving to a smallholding in Wales.
It was in Wales that Malachy first began to write and his first short story, Georgie Boy, won a prize in Ireland. He has since expanded upon this story and Georgie, his first young adult novel was published in 2001.
Malachy also writes for younger readers, and often draws upon the fairy and folk tales of his childhood for inspiration. For Orchard Books Malachy has written Ugly Great Giant has been described as "A thrilling story of triumph over the ugliest, meanest giant ever!" The Children's Bookshow.