Buffett -- who is worth an estimated $44 billion -- will give a large majority of the funds to the Bill & Melinda Gates Foundation.
Bill and Melinda Gates have been the only trustees of their foundation -- the world's largest philanthropic organization with funds totaling $30 billion -- but Buffett will soon join them, he told Fortune.
The foundation focuses on world health and the prevention of malaria, HIV/AIDS and tuberculosis. It also aims to improve libraries and high schools in the United States.
Bill Gates said he and his wife largely credit Buffett with inspiring them to give money and resources back to society. A mutual friend introduced the couple to Buffett in 1991.
Buffett's donation to the Bill & Melinda Gates Foundation is said to have the potential to be the largest philanthropic gift in history.