The donation, funded by the Gordon and Betty Moore Foundation, is the largest ever given to a private conservation group, according to Conservation International (CI).
The funds will be used in part to curb habitat and species destruction in a number of sensitive ecological areas around the world, such as rain forests and tropical wildernesses.
"The rate of species loss and habitat destruction demands immediate action," Gordon Moore said in a statement. "Collaboration is critical and we expect CI to continue to build strong alliances and maintain its commitment to solid science and innovative thinking."