Anscombe, who can play fly half or full back, will make the move to BT Sport Cardiff Arms Park this summer and join the exciting new-look squad under the guidance of new Director of Rugby Mark Hammett.
Highly-rated back Anscombe, who qualifies for Wales through his mother, has been a star performer in New Zealand and scored an impressive 268 points in his Super Rugby career.
Richard Holland, Chief Executive of Cardiff Blues, hailed the news that Anscombe has signed a contract with the region as a huge statement of intent for the future.
“We are absolutely delighted that Gareth has decided to join the Cardiff Blues family. I’m sure supporters right across Welsh rugby will be extremely excited about his arrival,” he said.
“When Mark Hammett was appointed as our new Director of Rugby we spoke about potential signings and Gareth was always top of that list. Hammer was extremely keen to bring him over and now we have concluded that deal after months of negotiations.
“Gareth’s signing is an absolutely crucial one for Cardiff Blues, especially following the departure of Leigh Halfpenny, and it shows our absolute intention to strengthen and bring world class players to our region.
Gareth Anscombe said: “My decision to leave New Zealand has been a tough one. I have loved every minute of career here in NZ and would like to say a special thanks to the Chiefs and Auckland Rugby for everything they have done for me.
“Much has been made about my Welsh eligibility and there is no doubt that my mother’s side of the family have always reinforced my Welshness. However, I am under no illusions and my focus is very much on the Blues and if the opportunity to represent Wales comes as a result of my performances on the pitch then of course I will take it.”