Shortly after The Independent broke the story on Wednesday afternoon, The Guardian announced that The Scott Trust had appointed Rusbridger to succeed Dame Liz Forgan as its chair when she reaches the end of her term in 2016.
The paper also confirmed that Rusbridger will step down from his current position next summer, following the appointment of his successor.
The Scott Trust exists to "safeguard the editorial future and independence of The Guardian".
Rusbridger told The Guardian: "In global journalism, there are a handful of roles that have the capability to redefine our industry. I am privileged to have held one of those roles for 20 years, a period in which successful newspapers have become global content providers, reaching audiences in dramatically new and valuable ways."
During his two-decade tenure, Rusbridger is said by media watchers to have pioneered The Guardian’s transformation from a print title to a digital platform with a global monthly audience of 111 million.
Forgan added: "Alan has been the outstanding editor of his generation. Fully embracing the opportunities of the digital age, he has built on the best traditions of his distinguished predecessors, transforming The Guardian from a print-only national newspaper into the world’s leading quality newspaper website."
Candidates to succeed Rusbridger include Katharine Viner, the editor-in-chief of Guardian US, and Ian Katz, Rusbridger’s former deputy who is now editor of Newsnight.