The 33-year-old, who has played 85 tests and a record 110 times for the Wellington Hurricanes, announced on Friday that he had signed a two-year deal to join French club Pau after the world title defence in England.
"I have loved my time playing rugby in New Zealand and really looking forward to what will be my last season here," Smith, who is a qualified lawyer, said in a news release.
"But it feels like the right time for me move on and try something different.
"Having a stint in France will allow me to spend more time as a husband and father, which was the main motivation for me when I made the decision."
Smith's regular centre partner Ma'a Nonu, flyhalf Dan Carter, prop Ben Franks, lock Jeremy Thrush and winger Frank Halai have already announced they will be heading to Europe after the Sept.18-Oct. 31 World Cup.
One of the craftiest players in world rugby, Smith makes up for a relative lack of power with his footballing ability, pace, anticipation and ability to read the game.
An automatic choice for the All Blacks when fit, he has scored 25 tries for his country and won 76 of the tests he has played, including the 2011 World Cup final against France.
"On behalf of the All Blacks, I want to publicly acknowledge the outstanding contribution Conrad has made - and continues to make - to the All Blacks," New Zealand coach Steve Hansen.
"He is a world-class player and leader in our team and we look forward to that continuing this season."