Crennan was born in Melbourne, one of six children born to World War 2 veteran, John Maurice Walsh, and Marie Therese (née Henley), Catholics of Irish descent. She attended Our Lady of Mercy College, Heidelberg and the University of Melbourne, where she received a Bachelor of Arts. She later received a Bachelor of Laws from the University of Sydney. Crennan also completed a Postgraduate Diploma (History) at the University of Melbourne on the constitutional history of the state of Victoria.Susan Maree Crennan AC – High Court of Australia
