Kelleher has agreed a deal which will start a month after the end of this year's World Cup and comes after fellow All Black Aaron Mauger confirmed a move to Leicester, while Chris Jack is reported to be close to signing with Saracens.
Hooker Anton Oliver has already stated his intent to end his connection with New Zealand rugby after the tournament, while representatives of Doug Howlett and Nick Evans have admitted contact with Heineken Cup clubs.
"Rugby's ruled my life since I've been involved with the All Blacks," the 30-year-old said.
"It's created the character I am and I'm very thankful for that, but I've got to a stage where I believe I need a new challenge in life and go out and experience a bit of the world.
"Now I'm looking forward to getting back in the Chiefs and getting some game time.
"I'm just thriving on that and while I haven't had much rugby lately I'm really looking forward to getting back on the field and thanking the Chiefs for what they've done for me by polishing off some good performances for them."
Meanwhile, Chiefs team-mate Keith Robinson has been told he may miss the rest of the season after picking up a training ground calf injury.
Coach Ian Foster said: "It's hard to say with Keith but it's a calf injury in the same spot as the last one.
"He's played two games with it and he's come through those fine. And then all of a sudden at one training it's gone bang, so obviously the scar tissue wasn't perfect.
"If you look at the last five to six weeks, I'd say that's a pretty good indication. It's very hard to see him coming back before that."
Mils Muliaina has also been ruled out of the rest of the campaign with a broken foot.