Melinda Gates

No 3. Melinda Gates, age 49

Cochair, Bill & Melinda Gates Foundation, United States

Melinda Gates has cemented her dominance in philanthropy and global development to the tune of $3.4 billion in giving in 2012 (most recent data available) and more than $26 billion in grant commitments since she founded the Bill & Melinda Gates Foundation with her husband in 1998. Her work has inspired other big donors and has changed way funders think about effective philanthropy: highly targeted campaigns coupled with data-driven monitoring and global collaboration.

The US businesswoman and philanthropist Melinda Gates. [Photo / IC]