She holds a Ph.D. in Marketing and Statistics, a Master of Science in Business, and a B.A. degree in Psychology from Cornell University.
Rosenfeld has been involved in the food and beverage industry for about 30 years. Her first job was at Dancer Fitzgerald Sample advertising agency in New York and she later joined General Foods in consumer research.
In 2004, Rosenfeld was appointed Chairman and Chief Executive Officer of Frito-Lay, a division of PepsiCo, where she focused on promoting healthy products.
Rosenfeld was appointed Chief Executive Officer of Kraft Foods in June 2006. She joined General foods which later became a part of Kraft foods. Among her many accomplishments at Kraft foods, she led the restructuring and turnaround of key business in the US, Canada and Moscow. She is active in a number of industry and community organisations, including the Economic Club of Chicago. She was appointed to the additional post of Chairman in March 2007, following Altria Group's spin-off of Kraft.
In 2008 she was placed sixth on The Wall Street Journal's "50 Women to Watch" list. Forbes rated Rosenfeld 2nd on the top 10 Most Powerful Women in 2010 and 10th in 2011.
In 2010, Rosenfeld earned total compensation of $19.288 million, placing her 48th on the Forbes Executive Pay.
Rosenfeld is a member of the Economic Club of Chicago. She also serves on the Board of Directors for the Grocery Manufacturers Association and the Cornell University Board of Trustees. She also sits on the Board of Directors of the Consumer Goods Forum.
On August 4, 2011, Kraft Foods said it plans to split into two publicly traded companies, with one focusing on its international snack brands like Trident gum and Oreo cookies and the other on its North American groceries business that includes Maxwell House coffee and Oscar Mayer meats. On December 5, 2011, Kraft announced that Rosenfeld will stay on as chairman of the $31 billion global snacking company, which will be called Mondelēz International, Inc. Tony Vernon, the president of Kraft Foods North America, will become CEO of the $17 billion North American grocery business, which will keep the Kraft Foods name.