The 36-year-old former North Harbour, Auckland Blues, Aironi, Munster and Ulster player made 77 appearances for the Welsh capital side over the past four seasons and became a cult figure on the terraces at the Arms Park.
Having come to Cardiff from Ulster in 2016, he played a major role in helping the Blues win the European Challenge Cup for the second time two years later.
“It’s sad not to have had one last run out at the Arms Park but with Covid-19, and everything that has come with it, there have been much bigger things to worry about,” said Williams.
“I’ve been blessed to play this game for so long and could never have imagined I would be a professional for 16 years and travel to so many brilliant places around the world.
“When I arrived in Cardiff, I knew this would be my last club and I have tried to make the most out of every single minute. It has been a really special time and the welcome my family received has been unbelievable.
“Winning the European Challenge Cup a couple of years ago is an obvious highlight, but I will also just miss the day to day and being with the boys around the place. I’m so grateful and have nothing but love for everyone at the Arms Park, from teammates and coaches, to the brilliant staff and sponsors, who have also been great to me, and of course the awesome fans.
“It has been a hell of a ride and I’m grateful to all the teams I have been part of. If I could carry on playing then I would, but the game has taken its toll and my wife has already sacrificed so much. I’m now looking forward to the next chapter with my family.
“We’re settled here now, this is our home and I’m looking forward to sharing a beer with some of the supporters on the terrace when we get back to the Arms Park.”
Born in Auckland to Samoan parents, Williams played rugby league through his youth and switched to union late. He was taken under the wing of Mark Anscombe, father of Gareth, and quickly progressed to North Harbour and Blues honours.
He played in 37 Super Rugby games for the Blues and earned four Junior All Blacks caps before making the move to Europe. He spent two years at both Munster and Aironi, before reuniting with Anscombe at Ulster.
He spent four successful seasons at Ravenhill and was named PRO14 Player of the Year in 2013. Renowned for his devastating ball carrying, soft hands and breakdown ability, he quickly established himself as a key figure both on and off the pitch at the Arms Park.
“Nick has been an enormous figure for us both on and off the field and will be missed by all of us at the Arms Park,” said Blues head coach John Mulvihill.
“His qualities on the pitch have always spoken for themselves, he is a big and physically imposing player but also possesses a quality skill set that defies his size and is very good over the ball.
“What people don’t always see is the leadership and cultural drive that he brings to our environment each and every day. He has been a great servant to Cardiff Blues and has had a major influence on the entire squad.”
