The supermodel's first article is due to feature in the forthcoming spring issue of the publication.
British Vogue editor Alexandra Shulman said: "I am absolutely delighted that Kate is going to work with us in this new role.
"Her undoubtedly brilliant sense of style, depth of fashion knowledge and understanding of what makes a wonderful image will be exciting to see on the pages of British Vogue. I am really looking forward to working with her on ideas."
According to the Vogue website, Moss will be a hands-on editor, joining the current Vogue fashion team of stylists and working with her choice of photographers and models.
Moss has starred on 33 British Vogue covers since her debut in March 1993.