Meet the 12 most powerful women on the planet

Title: CEO of Hewlett Packard Enterprise, chair of HP Inc.

Country: US

Age: 59

After taking the helm of IT company Hewlett Packard in 2011 amid internal corporate scandals, Meg Whitman set out to overhaul the company and revive its declining profits and revenues. She wrote off fruitless acquisitions, implemented thousands of layoffs, and ultimately split HP into two separate Fortune 500 companies, a change that took effect November 1. Whitman now serves as CEO of new brand Hewlett Packard Enterprises, which will focus on software and tech services, and is the chairman of HP Inc., which will center on personal computers and printers.

Previously the longtime CEO of e-commerce site eBay, Whitman’s personal net worth sits at a sizable $2.1 billion. When she took the position at eBay, the company only had 30 employees and $4 million in revenue, but by the time she left 10 years later, eBay was generating $8 billion in annual revenue and employed more than 15,000 people.

Whitman’s no stranger to politics either. Back in 2010, she unsuccessfully ran for governor of California, famously spending more of her own money on the campaign — at least $119 million — than any other self-funded politician in history.

Title: Former US Secretary of State, 2016 presidential candidate

Country: US

Age: 68

Hillary Clinton has come a long way since her stint as first lady, and she could find herself back in the White House if she wins the 2016 presidential election. The Democratic front-runner has support from an impressive 56% of her party, according to a November 13 poll by Reuters. This comes even after the "emailgate" scandal that revealed she had been using a personal email account instead of a government email while she served as secretary of state, showing that even despite her mistakes, her experience and popularity could still land her in office.

Clinton was the first female senator in New York and the first and so far only first lady to run for president herself. In addition to several high-profile endorsements from school unions, Clinton recently earned the support of the SEIU, a labor union two million members strong. As her list of backers continues to swell and her electoral chances improve, so does her sway and influence in American politics.

Title: Singer

Country: US

Age: 34

Arguably one of the biggest forces in the entertainment industry, Beyoncé shocked the nation in 2013 when she dropped a surprise album on iTunes without any promotion, which then went on to sell over two million copies and give us hits like “Drunk In Love,” “Partition,” and others. She's the most nominated woman in Grammy Awards history, with 53 nominations and 20 wins.

Beyoncé's influence reaches all corners of the globe. She encourages everyone to "#BEYGOOD" and make a difference in global issues like hunger, poverty, pollution, and health care. Beyoncé herself is a staunch advocate for women and children; she has taken humanitarian trips to Haiti to support pediatric care and reconstruction following the 2010 earthquake.

Title: CEO of IBM

Country: US

Age: 58

Last year, IBM CEO Ginni Rometty had to break some tough news: The tech company would be abandoning its years-long promise to hit $20 earnings per share by 2015. But the company's top leader has hatched a new plan: IBM will invest $4 billion to grow $40 billion in revenue in areas such as cloud computing, mobile, and big data by 2018. The plan would nearly double what IBM is making in these markets now, though it also means straying from the hardware focus that's defined IBM for decades.

Rometty's mandate is to keep one of tech's most iconic companies — which employs 380,000 people, on par in size with the population of New Orleans — relevant and profitable for the long haul, even if it means changing some of the most fundamental things about the company. The IBM lifer isn't apologizing for adapting. "Reinvention is not about protecting your past," she said at the Fortune Global Forum earlier this year.

Title: President of South Korea

Country: South Korea

Age: 63

South Korean President Park Geun-hye is the first female leader of her country — an especially impressive accomplishment considering South Korea has the highest level of gender inequality in the developed world. Her election generated the nation’s highest turnout rate in 15 years.

Park has the difficult but critical responsibility of diffusing threats from the ever-combative North Korea. Last year, she tried to get her mercurial neighbors to the north to abandon their nuclear-weapons program by promising humanitarian aid and an investment in its weak industries, but to no avail. Park has flexed her muscles by testing missiles that can reach all of North Korea, but Kim Jong-un hasn't blinked, and hasn't quashed any nuclear ambitions.

Title: CEO, OWN

Country: US

Age: 61

Worth nearly $3 billion, Oprah Winfrey is the only black female billionaire in the US. Despite a traumatic upbringing of living in poverty and enduring years of physical and sexual abuse, Winfrey became one of the most successful and beloved media personalities of the 21st century.

Winfrey is the founder of the award-winning production studio Harpo Productions — responsible for the 2014 critical darling "Selma" — and the Oprah Winfrey Network. She also owns the "The Oprah Winfrey Show," which brought in $300 million a year at its peak. She's a top cultural influencer, particularly among women, with a book club that is followed with cult-like dedication and an annual "favorite things" gift guide. Recently, she also extended the "Oprah effect" to the weight-loss industry when she bought a 10% stake in Weight Watchers in October and caused the stock to jump 105% as a result.

Title: Managing Director of the IMF

Country: France

Age: 59

Appointed managing director of the International Monetary Fund in 2011, Christine Lagarde is the first woman to head the organization, which serves as the economic adviser and backstop for 188 countries.

Along with the European Central Bank and the European Commission, the IMF under Lagarde has been preoccupied with propping up Greece's failing economy, which has required three bailouts in five years, the latest coming in August and requiring $95 billion of aid.

In November, Lagarde endorsed the Chinese yuan as an IMF reserve currency — a historic move that, if approved, would further cement China's rise as a top economic power.

Title: President of Brazil

Country: Brazil

Age: 67

Dilma Rousseff, Brazil's first female president, leads the largest country in Latin America and the seventh-largest economy in the world. Rousseff is credited with nearly eradicating extreme poverty in Brazil during her first term by raising the monthly stipend for struggling families.

But Rousseff has hit a rough patch lately, and it appears to be getting worse. Protests broke out and gained traction in March in part because of Brazil's crumbling economy. The country's growth has plummeted — low commodity prices, high interest rates, and austerity measures are partly to blame — and it officially entered a recession in 2015. The value of its currency dropped by 45% this year through mid-November.

Also contributing to her near record-low approval rating: A group of high-profile lawyers filed for the impeachment of Rousseff in October in connection to the corruption scandal involving the state-run oil company Petrobras (Rousseff has maintained her innocence).

Title: CEO of Fidelity

Country: US

Age: 53

In late 2014, Abigail Johnson succeeded her father Edward as CEO of Fidelity, the second-largest mutual fund company in the US, which oversees more than $5.2 trillion in assets. Johnson keeps a low profile, but it’s no secret she was groomed to take over the company from an early age. She started working at the firm in high school, and officially joined Fidelity as an analyst in 1988. Since 2012, Johnson had served as president.

Johnson wasn't slow to wield her power and effect change after assuming the top role last year, quickly moving to cut costs and fire ineffective managers. She's no stranger to power plays, reportedly maneuvering to oust her father in 2004 over a disagreement in vision (the effort failed, and Edward remains the chairman of the company).

Not only is the new Fidelity CEO responsible for millions of Americans' retirement accounts, but through her roughly 24% stake in the company, Johnson holds a personal fortune of $18.5 billion, making her one of the wealthiest women in the world.

Title: Chair of the Board of Governors of the Federal Reserve

Country: US

Age: 69

As the head of the Federal Reserve — the first woman to hold the job — Janet Yellen is the guardian of the US economy. The results have been good so far: The US is closing out the year with a period of growth, adding 271,000 jobs in October and lowering unemployment to 5%, according to the latest jobs report. The strong economic performance has many speculating that an interest rate hike from the Fed is imminent. It would be the first in almost a decade.

It's a hefty decision with profound economic implications, and investors and company executives worldwide parse Yellen's every word for hints to her plans. A small rate hike would indicate the economy is thriving and strong, but some worry that lifting rates too early will damage individuals' spending ability and hamper growth. But too much growth and improvement in the labor market without a rate hike could lead to inflation. Either way, Yellen holds a position of immense power, and her decision will affect the entire country.

Title: Chancellor of Germany

Country: Germany

Age: 61

With 10 years and three terms in office under her belt, German Chancellor Angela Merkel is a strong and indispensable leader in Europe. She has faced a host of challenges throughout her tenure and come out on top: She helped hold the eurozone together during the financial collapse and global recession, she has stood up to Russian President Vladimir Putin in his aggression toward Ukraine, and, currently, she's managing Europe's refugee crisis. At her hand, Germany stands above the rest of Europe with a strong economy and low unemployment rate. Though she's not universally liked, Merkel has proved a stabilizing force amid turmoil.