2009 rank: 32
Age: 55
Some three decades after starting as a crew member in Dayton, Fields took charge of the company's 14,000 U.S. restaurants in January. She boosted same-store sales and operating income in her first two quarters on the job, with the help of frappes and smoothies.
NEXT: Susan Wagner
Last updated September 30 2010: 2:47 PM ET