In March 1944 Williams enrolled as an external student at the University of London in the Faculty of Law. He completed his final LLB examinations in June 1946. He graduated with Second Class Honours in Law in June 1946. He was admitted as a barrister on 19 November 1946 and was appointed a Queen's Counsel on 4 March 1965.
Williams was appointed as a judge of the Supreme Court of Queensland on 13 May 1971 and served until he retired on 17 February 1984.
Williams was appointed to head the 1977 to 1980 Royal Commission Inquiry into Drugs.
Williams had numerous other commitments, including being chairman of the Queensland Turf Club for 11 years up to 1991. The Sir Edward Williams Handicap is run on Queensland Oaks day at Eagle Farm racecourse, for his service of over 30 years to the QTC.