The 36-year-old will bring his rugby career full circle in New Zealand, after playing for Toulon in the French Championship for three years.
The Blues believe Nonu will play a key role at the club, adding crucial experience to a youthful Blues backline and be influential in a 2019 season that will pose new challenges.
“Our review showed that our backline, while talented and exciting, lacked an experienced figure on a regular basis in the midfield due to injury,” said coach Tana Umaga.
“Next season will throw up some other challenges with a new format without the international break. And players in line for the World Cup, like Sonny Bill Williams, will likely be monitored more closely.”
Umaga said that included the likes of Rieko Ioane, who he wants to see back in his likely All Black position on the wing as a priority in preparation for the Rugby World Cup.
STORY | @crusadersrugby pick up a young superstar who is ready to kick-off his #SuperRugby career.
“Hopefully next year will be a year to build and to be successful. That is the challenge I am looking forward to.
“I know the Blues have had some tough times in the last few seasons but I am excited to play with some of the young and up-and-coming players who will have long careers and rejuvenate this place.
Nonu said he is impressed with the facilities at the Blues which he says rival those at the top level in France.
“It is a nice facility, top of the range in this country that I have seen. They have a lot of facilities like this in France but this is the best I have seen here. Hopefully we can use what we have here as tools to perform on the field.”
Nonu says he will bring his experience to the club and its young players.
“I have been playing rugby a long time. I’ve known first-hand the highs and the lows of a playing career on and off the field and I am looking forward to giving my best and proving that I can still play at this level.”
Ahead of this weekend's Test against South Africa, we throwback to 2?0?1?0? when Kieran Read was simply UNSTOPPABLE just five metres out from the try line.