He has been President of both the New South Wales and Australian Bar Associations. Gyles was a Judge of the Federal Court of Australia from 1999 to 2008 and then an Acting Judge of the Court of Appeal of the Supreme Court of New South Wales.
He has held leadership positions in both the New South Wales and Australian Bar Associations. Gyles served as a Judge of the Federal Court of Australia from 1999 to 2008, followed by an Acting Judge position on the Court of Appeal of the Supreme Court of New South Wales.