"It means a new challenge I suppose and kind of a daunting one. I'll find out what it really means when I turn up to work in the New Year," he told Radio NZ after the announcement.
Justice Williams graduated with a Bachelor of Laws from Victoria University in 1986 and joined the faculty as a junior lecturer in law, before going on to gain a masters degree with honours from University of British Columbia in 1988.
After leaving Canada, Justice Williams joined commercial law firm Kensington Swan, where he established the first unit specialising in Maori issues in a major New Zealand law firm.
He became a partner at Kensington Swan in 1992, but left to co‑found the new firm of Walters Williams & Co in Auckland and Wellington during 1994.
"We've got to a point where the changes over the last generation have produced a kind of critical mass of Maori legal talent," the Wellington-based judge told Radio NZ.
"We'll see that slowly making its way through the pipeline over the next generation I think, which is great."