O'Toole grew up in wartime Derbyshire, England and was educated in Brighton and Cambridge. He has a Master of Arts degree from the University of Canterbury, a Master of Education from the University of Newcastle and a Diploma of Dramatic Education from the University of Durham. O'Toole became an English and Drama teacher before working for various companies as an actor-teacher, writer and education officer. He was granted a Fellowship to study and write Theatre in Education (1977). He then moved to Australia and by 1986 was Head of Expressive Arts at the Mount Gravatt Campus of the Brisbane College of Advanced Education. Since then he has been an associate professor in Drama and Drama Education at Griffith University and more recently a professor in the Faculty of Education at the University of Melbourne. He was awarded an ARC Linkage Project grant 2007-2009 on 'Mapping and augmenting engagement, learning and cultural belonging for children undertaking ArtPlay workshops'.
O'Toole has written plays for and with particular groups of clients and has been Writer-in-Residence at La Boite Theatre, Brisbane. He has also tutored at the Interplay '85 International Young Playwrights Festival and read for the Australian National Playwrights' Conference. O'Toole has written widely on theatre in education with a more recent shift into exploring its use in adult learning and empowerment in works such as Drama for Life : stories of adult learning and empowerment (2000) and Cooling Conflict : a new approach to managing bullying and conflict in schools (2005).