The World's Most Powerful Women

Women are making waves in business, politics and nonprofits around the world. Their influence is growing.

Forbes' Power Women list isn't about celebrity or popularity; it's about influence. Queen Rania of Jordan (No. 75), for instance, is perhaps the most listened-to woman in the Middle East ; her Twitter feed has 600,000 followers.

In assembling the list, Forbes looked for women who run countries, big companies or influential nonprofits. Their rankings are a combination of two scores: visibility--by press mentions--and the size of the organization or country these women lead.

In Pictures: The 100 Most Powerful Women
Click here to see the full list of The 100 Most Powerful Women

At No. 1, for the fourth consecutive year, is German Chancellor Angela Merkel. Up for reelection this September, she is leader of the world's fourth-largest economy. She faces a tough year: Germany 's GDP is expected to shrink this year despite a small uptick in the second quarter.

Federal Deposit Insurance Corp. Chairman Sheila Bair, who remains in the No. 2 spot, has presided over the orderly takeover of 77 banks so far this year. In fighting for more power for her agency, she has butted heads with Fed Chairman Ben Bernanke and U.S.Treasury Secretary Timothy Geithner.

Chief Executives Indra Nooyi of PepsiCo (No. 3), Cynthia Carroll of Anglo American (No. 4) and Irene Rosenfeld of Kraft Foods (No. 6) rank among the world's most powerful businesswomen and are tasked with steering their companies through unusually challenging times.

Singapore 's sovereign wealth fund, Tamasek, has delivered extraordinary average annual returns of 18% under the leadership of Ho Ching (No. 5). She is currently seeking a successor.

This year's list includes several notable newcomers--from the U.S. and abroad. The recently approved Supreme Court Justice Sonia Sotomayor debuts at No. 54. She will be the third woman and the first Hispanic in the top court. First lady Michelle Obama, a champion for working women and the families of the U.S. military, appears at No. 40.

Among the female U.S. Cabinet secretaries, Homeland Security Secretary Janet Napolitano and Health and Human Services Secretary Kathleen Sebelius rank at No. 51 and No. 56, respectively. Meanwhile, SEC Chair Mary Schapiro (No. 55) is in the midst of a maelstrom, as Congress weighs new regulations of the financial services industry.

All eyes are also on Iceland 's new prime minister, Johanna Sigurdardottir (No. 74) as she seeks to recapitalize the banks of her small island nation, which recently came very close to complete economic collapse. She is an advocate of Iceland 's entry into the E.U. and adoption of the euro--views not entirely popular with her people.

In the tech sector, Carol Bartz (No. 12), who was appointed CEO of Yahoo! in January and is the former chief of Autodesk, faces tremendous pressure. With the Microsoft search deal behind her, she needs to show investors that she can quickly shore up the top and bottom lines.

An engineer by training, Ursula Burns (No. 14), was recently appointed CEO of Xerox, and is the first African-American woman to run a major U.S. public company.

This year, instead of including highly placed media figures, we spotlighted them with a list of their own.

In Pictures: The 100 Most Powerful Women
Click here to see the full list of The 100 Most Powerful Women

1. Angela Merkel, Chancellor of Germany
2. Sheila Bair, Chairman, Federal Deposit Insurance Corp.
3. Indra Nooyi, Chief executive, PepsiCo
4. Cynthia Carroll, Chief executive, Anglo American
5. Ho Ching, Chief executive, Temasek
6. Irene Rosenfeld, Chief executive, Kraft Foods
7. Ellen Kullman, Chief executive, DuPont
8. Angela Braly, Chief executive, WellPoint
9. Anne Lauvergeon, Chief executive, Areva
10. Lynn Elsenhans, Chief executive, Sunoco
11. Cristina Fernandez, President of Argentina
12. Carol Bartz, Chief executive, Yahoo
13. Sonia Gandhi, President, Indian National Congress Party
14. Ursula Burns, Chief executive, Xerox Corp.
15. Anne Mulcahy, Chairman, Xerox Corp.
16. Safra Catzm, President, Oracle
17. Christine Lagarde, Minister of Economy, Finance & Employment
18. Gail Kelly, Chief executive, Westpac
19. Marjorie Scardino, Chief executive, Pearson Plc.
20. Chanda Kochhar, Chief executive, ICICI Bank
21. Mary Sammons, Chief executive, Rite Aid Corp.
22. Michelle Bachelet, President of Chile
23. Paula Reynolds, Chief restructuring officer, AIG
24. Carol Meyrowitz, Chief executive, TJX Companies
25. Andrea Jung, Chief executive, Avon