First Lady of the United States
It is no revelation that Michelle Obama  is more popular than President Obama. While she has the intellect to make policy, as first lady she doesn't have to. Instead Mrs. Obama  concentrates on youth, applying style and insight in the Let's Move!  campaign, promoting new nutritional standards with Choosemyplate.gov  and extending her message through her trip to South Africa . That she's lovely, provides intellectual and emotional support for her husband and is a great mom are just extras for the eighth most powerful woman in the world, according to Forbes magazine.
Captions by Frank McCoy
Serial entrepreneur, publisher, media star and philanthropist Winfrey , 57, is worth more than $2.7 billion and ranks No. 14 on the Forbes list of the world's most powerful women. Winfrey , a graduate of Tennessee State University, may have left her popular television show behind, and her Oprah Winfrey Network  is struggling, but she still made an estimated $290 million in 2010. Her philanthropic endeavors include the Oprah Winfrey Foundation, the Oprah Winfrey Leadership Academy for Girls  in South Africa and Oprah's Angel Network.
There is no doubt that mother-to-be Knowles , 30, is a wonderful entertainer and multiproduct spokeswoman, but her influence is of a different type from that of the other black women on this list. Girls who wish to emulate her should consider how Knowles , who ended her professional relationship with her father this year, is now in control of both the business and the entertainment sides of her life. Forbes ranks her at No. 18.
Chairman and CEO
Last year Xerox, under the leadership of CEO Burns , had revenues of $21 billion. During her 30-year career at the imaging giant, Burns , who earned a B.S. and an M.S. in mechanical engineering, rose from intern to president and became chairman and CEO in 2010. She is the first black woman to lead a key publicly traded company, and does so rocking a stylish natural hairdo. View other top black women in technology . She is No. 27 on the Forbes list of most powerful women.
President and CEO
In 2010 the global humanitarian organization that Gayle  leads employed about 10,000 people and helped 82 million people fighting poverty in 87 countries. The physician  with a master's degree in public health from Johns Hopkins University joined CARE in 2006. Since then she has reinforced empowerment of girls and women and used nongovernmental and corporate partners to expand CARE's reach. Previously she worked for 20 years at the Centers for Disease Control and Prevention, primarily on HIV/AIDS. She ranks No. 36 on the Forbes list.
President of Liberia
Since her election to lead the tiny West African nation in 2006, Johnson Sirleaf  has presided over Liberia's rebuilding after years of strife. Her efforts have resulted in greater national security and have attracted aid donors, which led to $4 billion in debt relief and more than $16 billion in mining, agriculture and forestry investments. The graduate of Harvard University's Kennedy School of Government and former World Banker is Africa's first female head of state . She is ranked No. 62 by Forbes.
Finance Minister of Nigeria
When Okonjo-Iweala (No. 87) left her post as managing director at the World Bank to become Nigeria's finance minister, she brought strong credentials. From 2003 to 2006, Okonjo-Iweala was finance minister under ex-President Olusegun Obasanjo and was known as an advocate of financial stability and transparency. During recent ministerial nomination hearings, Okonjo-Iweala criticized  Nigeria's budget allocations, saying that the country was living beyond its means. She also asked why Nigeria, a major oil exporter , did not produce related products for domestic consumption.
President and CEO
Robert Wood Johnson Foundation
In 1984 Lavizzo-Mourey  was a RWJF scholar. In 2003 she became the first female leader of the nation's largest health-focused philanthropic group. The RWJF, with an endowment of $10 billion, has current initiatives against childhood obesity and smoking and administers more than $400 million in charitable and program distributions. Lavizzo-Mourey , a Harvard-trained physician with a Wharton School MBA, recently co-directed a congressionally mandated study on racial disparities in health care. She ranks No. 95 on the Forbes list.
ArcelorMittal South Africa
Since 2008, South African Nyembezi-Heita, 51, has been CEO of a subsidiary of ArcelorMittal, the world's biggest steel maker, owned by the Mittal family of India. For Nyembezi-Heita  (No. 97 on the Forbes list), an ex-Vodaphone senior executive who has a Master of Science in electrical engineering from California Institute of Technology and an MBA, this year has been a challenge because a weakened construction sector has purchased less steel.