Clinton has already made history by becoming the first female presidential nominee of a major US political party in her bid for the White House in November.
“This is historic, just as Barack Obama was historic. There is no question about that,” said Ester R. Fuchs, professor of public affairs and political science at Columbia University, referring to the first black US president.
Across the Atlantic, “Iron Lady” Margaret Thatcher broke the glass ceiling decades ago when she became British prime minister in 1979, and last month May did it again.
Chancellor Angela Merkel has led Germany since 2005, while South Korea, Chile, Brazil, Bangladesh and Liberia are also led by women – as is the International Monetary Fund (IMF).
But these leaders remain in a minority and their numbers are only gradually increasing.
A study by the Pew Research Centre last year found women led only about 10 per cent of UN member states.
“Even while the number of female leaders has more than doubled since 2005, a woman in power is hardly the norm around the world,” it said.
Sheet of steel
There are regional variations, with Finland, Norway and Iceland well used to female leadership, and South and Southeast Asia and South America performing better than elsewhere, according to UN Women, the United Nations body championing gender equality.
Past leaders include Indira Gandhi in India, Benazir Bhutto in Pakistan, and Argentina’s Cristina Kirchner, while Aung San Suu Kyi is currently de facto leader of Myanmar.
But it took until 2005 for Africa to have its first female elected leader, in Liberia’s Ellen Johnson Sirleaf – although the continent has a better record on ministers.
At the start of 2015, only 17.7 per cent of all government ministers in the world were female, but it was more than 30 per cent in Cape Verde, Rwanda and South Africa.
In Japan, Yuriko Koike last month became the first female governor of Tokyo, a rare breakthrough in a male-dominated society.
One of the 64-year-old’s key tasks will be smoothing the capital’s troubled road to the 2020 Olympics, hit by a series of embarrassing scandals and soaring costs.
She has acknowledged it was a struggle to get where she is, once noting that Japan did not so much have a glass ceiling as a “sheet of steel” that women had to break through.
In Italy, another country where men still hold sway, Virginia Raggi and Chiara Appendino were elected this year as mayors of Rome and Turin respectively.
But Sofia Ventura, professor of political and social sciences at the University of Bologna, said their elections cannot yet be called a turning point.
“We are in a complex phase, with steps forward but strong cultural habits,” she said.
In Spain, which has been in political deadlock for months, the advent of more women could help bring a different style of politics, said Juan Jose Garcia Escribano, professor of political sociology at Spain’s University of Murcia.
“I believe that Spaniards will find it more and more normal that the country could be run by women who could find solutions to problems, such as economic ones, that men largely created and seem unable to solve,” he said.
Arantxa Elizondo, a professor at the University of the Basque Country, said women on the left of politics or in reformist movements are forging a new path.
Citing Madrid mayor Manuela Carmena and Barcelona’s Ada Colau, she noted they have raised issues that were previously excluded from politics, “issues related to the daily lives of people”.
The problem is that “there is a different standard for a woman than there is for a man”, noted Fuchs.
“When you look at Hillary Clinton’s history you can see it so clearly. They want a man to be tough but when a woman is tough that means she is difficult as opposed to strong.”
So when will a woman lead the United States?
“In 1937, when Gallup did its first poll on it, only 33 per cent of the country said they would vote for a woman,” Fuchs said. Since 2012, this figure has been 95 per cent.
Whether this translates into actual votes remains to be seen.