The former Vogue Paris editor Carine Roitfeld will be teaming up with the US title's creative director Stephen Gan on several stories a year from next March onwards, which will feature across all 26 international editions of the magazine.
Duncan Edwards, president and CEO of Hearst, said: "This collaboration marks the first time anything like this has been done. She is a visionary in the fashion world and we are so happy to be working with her."
Carine added: "I am thrilled to be contributing to Bazaar, a brand with a rich history of creativity. Working with Stephen and a roster of talented photographers will be a wonderful collaboration and one that will give these stories a truly global audience."
The legendary fashion boss has been busy since handing the job of editing the French style bible over to Emmanuelle Alt in December 2010.
She has styled several Chanel campaigns, launched her new magazine, CR Fashion Book, and created her own make-up line for MAC cosmetics. Carine will now also be in charge of styling several Harper's Bazaar covers a year.
The fashionista's new allegiance to Hearst magazines marks a clear break from Vogue's publishing group, Conde Nast.
She recently said of her successor Emmanuelle: "Maybe this was not supposed to be a friendship. If I look at the balance, maybe I lost some people I thought were my friends, but I made so many new friends. I am very happy, in the end, because I am the winner."