"Leinster are a very competitive side and I am looking forward to challenging myself in another professional environment. I am not ruling out returning to NZ rugby. At 24 I feel my best years are still to come. But for this stage of my life and with an eye to the future, I have to set myself and my future family up so they can have every opportunity in life to succeed.
"Everyone knows about Leinster and what they have achieved over the last eight years or so but I have also spoken to a few people that I know in Leinster and they have nothing but positive things to say about the club and city. I also really enjoyed my visit to Ireland with the Maori All Blacks last year," said Lowe.
The five-time Maori All Black could link up with Kiwis Hayden Triggs and Jamison Gibson-Park at the Irish province, who also currently possess the likes of Isa Nacewa and Zane Kirchner, as well as a slew of Irish internationals, led by Jonathan Sexton and Rob Kearney.
"James is a quality and still relatively young outside back that we have been tracking for some time, so we are delighted that he has agreed to join us," said Leinster coach Leo Cullen.
Chiefs coach Dave Rennie paid tribute to Lowe's contribution to the Chiefs over the past four seasons.
"His unique skillset, leadership and attacking mindset makes him one of the best left wingers in the world. It is a smart signing by Leinster. James is a top man, great in the community and has been a pleasure to work with."
