He was appointed a Queen’s Counsel in 1988 and practised as such up until his appointment as a Master of the High Court in 1989 but, after declining reappointment as a Master, returned to practice as a barrister in Auckland from 1993-1995. During his time in Palmerston North he was active as a member and President of the Manawatu District Law Society and served on a number of Committees of the New Zealand Law Society, including chairing the Courts and Tribunals Committee from 1986-1989.
Justice Williams served as a Palmerston North City Councillor from 1983-1989.
Justice Hugh Williams has also made a substantial contribution to tertiary education, including as a member of the Council of Massey University for some 25 years, where he served as Chancellor from 1991-1997.
Justice Hugh Williams continues in full-time service as a Judge of the High Court pursuant to an Acting Warrant. He also holds appointment as a Judge of the High Court of the Cook Islands and has sat in that jurisdiction.
In 2009 the Minister of Justice appointed Justice Hugh Williams President of the Electoral Commission, an office he still holds.