Leigh is renowned for his passion and as a leader in his chosen profession in Orthodontics. After graduating with a Bachelor of Dental Studies from the University of Western Australia, he then went on to complete a speciality-training course in Orthodontics from the Royal Dental College in Denmark. Leigh was awarded a Masters in Dental Science from the University of Aarhus, Denmark upon which his research thesis was nominated for the American Young Researchers Award.

Leigh completed his PHD in Odontology in June 2010 in Denmark. He currently holds several academic positions including Honorary Clinical Associate at the University of Sydney and Visiting Clinical Professor at the University of Aarhus, Denmark. In addition, Leigh was president of the Manly Warringah Dental Study Group for many years until recently and continues to serve on the committee and attends meetings and lectures regularly.