Helen Clark has been ranked 34th in Forbes magazine's annual list of the world's most powerful women.
Last year the former New Zealand Prime Minister, who heads the United Nations Development Programme, was ranked 50th.
German Chancellor Angela Merkel tops the 2012 list, followed by US Secretary of State Hillary Clinton.
Others in the top ten include Michelle Obama, Sonia Gandhi and Melinda Gates.
The magazine determines rankings by wealth, media presence and overall impact.
Sixteen women enter the list for the first time, including singer Jennifer Lopez, former US Republican presidential candidate Michele Bachmann, Meg Whitman of Hewlett-Packard and Marissa Mayer of Yahoo.
For Ms Merkel, it's the second year in a row at the top, reflecting her role in trying to resolve the European Union's financial crisis.
Ms Clinton, the magazine says, "has had a formidable past 12 months" and is set to resign at the end of the year.
Singer Lady Gaga makes it to 14th and at 26 years old is the youngest. The oldest, Queen Elizabeth, who is 86, is 26th in the ranking.