The five-year agreement will begin next season, and will see the tyre manufacturer’s logo appear on all the Blues’ shirts, ranging from the first team to the development squad.
The deal is worth a reported £40 million (Sh5,644,149,850.2), far surpassing the west London giants’ previous £18m-a-year deal with Samsung.
Chelsea chairman Bruce Buck confirmed the news, saying: “Chelsea and Yokohama are a perfect fit. Both are global organisations with a focus on performance and innovation, as well as having huge ambition and an unwavering culture of success.
“We believe that Yokohama will play a key role in helping us drive our global expansion in international markets, such as the United States, where they have operated with distinction for many years.
“Also, of course, Chelsea having such an esteemed and historic Japanese company as our partner enables us to accelerate our development in their home market too.
“We are also looking forward to working with Yokohama on our community projects around the world through the Chelsea Foundation, when together we can use the power of sport as a force for good.”
Yokohama chairman Tadanobu Nagumo added: “This shirt partnership with Chelsea will give Yokohama an opportunity to showcase our company to a huge worldwide audience thanks to Chelsea’s ever-growing popularity.”