Oliver Jeffers was born in Port Hedland and raised in Belfast, Northern Ireland. He visited the US and Australia in 1999-2000 and worked in Sydney as a freelance illustrator and painter. In 2000, Jeffers returned to Ireland to complete his university degree at the University of Ulster. His artwork has been exhibited in Sydney, Melbourne, New York, London and Belfast. and his chlidren's books have won numerous awards.
Only co-authored works by Jeffers are listed in AustLit. A 2012 interview makes the following statement about his heritage: 'Jeffers was born in Australia, where his parents fled from the turmoil of Northern Ireland in the 1970s, but he was only ten-months old when they returned to Belfast and so considers himself an Irishman with all the influences that brings' (Magpies : Talking about Books for Children, 27.3, July 2012, p.4).