Chelsea have signed a kit sponsorship contract with Nike understood to be worth £900 million (NZ$1.5b) over 15 years, the biggest in the club's history.
The Blues had announced they were parting company with adidas at the end of the season in May, after the pair decided to terminate their current deal six years early.
The 15-year deal, at £60m per season, is set to become the biggest in the history of sport in this country.
Adidas' shirt deal was worth £30million annually - a figure that has been doubled by their American sportswear rivals, despite the fact Chelsea are not competing in Europe this season.
The long-term agreement sees Nike take over from the beginning of the 2017-18 season, producing strips for the first-team, academy and ladies teams and a full range of clothing.
Chelsea director Marina Granovskaia said: 'This is an incredibly exciting and important deal for the club. Like Chelsea, Nike is known around the world for its excellence and innovation and we look forward to working together in what is sure to be a successful partnership.