Simon is the Kim Santow Chair of Law and Social Justice at the University of Sydney Law School, and a legal consultant at the law firm Chalk & Behrendt. He has been a solicitor and volunteer at Redfern Legal Centre, Principal Solicitor and Director of Kingsford Legal Centre, and a board member of many other legal centres. In his role at Chalk & Behrendt, Simon advises Aboriginal organisations on land rights and corporate governance issues. Simon has also been Director of the NSW Law and Justice Foundation, Chair of the ACT Law Reform Advisory Council, adviser to the Parliamentary Joint Committee on Human Rights, and a judicial member of the NSW Administrative Decisions Tribunal. He has practised, taught and written extensively in anti-discrimination and human rights law. Simon became chair of the Board in 2019.