The 24-year-old appeared in every national provincial Premiership match for the Counties Manukau Steelers last year when they won the Ranfurly Shield and made the semi-finals of the ITM Cup Premiership.
Aki also started 12 games in midfield, scoring six tries, in his debut season for the Chiefs on their way to winning the title.
He has exploded on to the big stage under the expert tutelage of Wayne Smith, Tana Umaga and Dave Rennie who has described the young player as 'a very quick, aggressive and evasive ball carrier. Bundee is a competitive character who is destructive defensively'.
Speaking about the province's latest signing, Connacht head coach Pat Lam said: "This is a fantastic coup for Connacht. It's great to be able to replace the loss of Eoin Griffin and Kyle Tonetti with the calibre of a player like Bundee.
"He is only 24-years-old and has already shown with the Chiefs and Counties Manukau what a thrilling prospect he is for the game.
"It's very exciting to be adding him to our young Irish-qualified back-line here at Connacht and he will bring a real attacking edge in midfield.
"He is a hard-working and talented individual and I believe that he will greatly contribute to the Connacht culture we've been developing and the vision we have laid out for the team. We're very much looking forward to welcoming him here."
On the day of the Chiefs' victory over the Melbourne Rebels, in which Aki started in the number 12 jersey, the player himself commented: "I'm delighted to be able to confirm my move to Connacht Rugby.
"This is a huge opportunity for me and my family and I'm really excited by the new challenge. I spoke with Pat (Lam) and was very impressed with the aspirations he and the team have for Connacht and its future. It's definitely something I want to be a part of.
"Right now, I'm excited about getting back to playing with the Chiefs where I've thoroughly enjoyed my time. There is a lot of rugby to be played before I start the next chapter with Connacht."
Aki will move to Connacht at the conclusion of the New Zealand ITM Cup season.