Williams was born in 1934 and educated at Feilding High School.
He graduated from the University of New Zealand at Auckland in 1960.
A noted defence lawyer, Williams represented high-profile clients including Terry Clark, Ronald Jorgensen, Arapeta Awatere and Winston Peters, and was involved in having the conviction of Arthur Allan Thomas for the murders of Harvey and Jeannette Crewe overturned.
During his 60-year career, he appeared in over 100 murder trials.

Williams was a long-time advocate for the humane treatment of prisoners in New Zealand, and served as the head of the New Zealand Howard League for Penal Reform.
He was the foundation president of the NZ Criminal Bar Association.

Williams was appointed a Queen's Counsel in 1987.
In 1990, he was awarded the New Zealand 1990 Commemoration Medal, and in the 2015 New Year Honours Williams was appointed a Knight Companion of the New Zealand Order of Merit for services to the law.
A private investiture was held at his home on 11 April 2015, as it was feared he might not live until the scheduled investiture on 6 May 2015 at Government House in Auckland.
He died from prostate cancer at his home in the Auckland suburb of Ponsonby on 9 June 2015, survived by his wife, Lady Heeni Phillips-Williams.
Williams was born in 1934 and educated at Feilding High School. He graduated from the University of New Zealand at Auckland in 1960. A noted defence lawyer, Williams represented high-profile clients including Terry Clark, Ronald Jorgensen, Arapeta Awatere and Winston Peters, and was involved in having the conviction of Arthur Allan Thomas for the murders of Harvey and Jeannette Crewe overturned. During his 60-year career, he appeared in over 100 murder trials. 
Williams was a long-time advocate for the humane treatment of prisoners in New Zealand, and served as the head of the New Zealand Howard League for Penal Reform. He was the foundation president of the NZ Criminal Bar Association.
Williams was appointed a Queen's Counsel in 1987. In 1990, he was awarded the New Zealand 1990 Commemoration Medal, and in the 2015 New Year Honours Williams was appointed a Knight Companion of the New Zealand Order of Merit for services to the law. A private investiture was held at his home on 11 April 2015, as it was feared he might not live until the scheduled investiture on 6 May 2015 at Government House in Auckland. He died from prostate cancer at his home in the Auckland suburb of Ponsonby on 9 June 2015, survived by his wife, Lady Heeni Phillips-Williams.
Peter Williams (lawyer)