President, McDonald's USA McDonalds 2010 rank: 25 Age: 56
As head of the fast-food giantís 14,000 U.S. restaurants, Fields increased 2010 U.S. revenue 2% and operating income 7% her first year in the role. The McDonaldís veteran
also headed up the companyís National Hiring Day in April, signing on 62,000 new employees.
The list is compiled by FORTUNE editors, who consider four criteria: the size and importance of the womanís business in the global economy, the health and direction of the
business, the arc of the womanís career (resume and runway ahead), and societal and cultural influence.