Simon is a Professor of Law at the Australian National University, where he is Director of Law Reform and Social Justice. He researches and writes in discrimination, human rights, access to justice and public interest lawyering.
From 1996-2011 he was a part-time judicial member of the NSW Administrative Decisions Tribunal in the Equal Opportunity Division. He is a past President of Australian Lawyers for Human Rights, and a former Director of the NSW Law Foundation.
In 2002 he was awarded a Medal in the Order of Australia for legal services to the socially and economically disadvantaged.