The pledge comes amid a United Nations effort to eradicate extreme poverty by 2030, a goal set on Friday during a special summit at the global body.
The Internet became commonplace in developed countries in the 1990s, but UN officials estimate that half the world does not have reliable access -- especially women and girls, whose education is vital to development.
"When people have access to the tools and knowledge of the Internet, they have access to opportunities that make life better for all of us," said a declaration signed by Zuckerberg and Bill and Melinda Gates, who have devoted their wealth to philanthropy.
"The Internet belongs to everyone. It should be accessible by everyone," the declaration said.
Zuckerberg, swapping his trademark hoodie for a suit and tie as he appeared at the United Nations, said that for every 10 people connected to the Internet, one is lifted out of poverty.
Read: Facebook formally launches its limited-free internet service in Pakistan
"The Internet is more than just a network of machines; it is the key driver of social and economic progress in our time," Zuckerberg told a luncheon at the UN headquarters attended by German Chancellor Angela Merkel.
The 31-year-old entrepreneur pointed to the role of the Internet in empowering otherwise voiceless people in places such as Syria, where civil war is producing a refugee exodus.
"A 'like' or a post won't stop a tank or a bullet, but when people are connected, we have the chance to build a common global community with a shared understanding -- and that's a powerful force," he said.
He estimated that spreading the Internet could also bring affordable education to 600 million children who would otherwise go unschooled.
Other signatories included Jimmy Wales, co-founder of free online encyclopedia Wikipedia, and U2 frontman Bono on behalf of his One anti-poverty campaign.
Jamie Drummond, global executive director of One which spearheaded the push, called on every country to come up with an "urgent plan" to meet the Internet access goals.
The campaigners did not announce funding on their own, but the United Nations has said that meeting the new global goals will cost between $3.5 and $5 trillion per year.
The Bill and Melinda Gates Foundation on Saturday launched its own roadmap, which put a top priority on improving the health and education for girls.
Releasing the report, UN Secretary-General Ban Ki-moon said that more than $25 billion has been committed so far to meeting the goals, led by $3.3 billion from the United States and large pledges from Canada, Germany and Sweden.
Melinda Gates, speaking to reporters in advance of the launch, said that the health and education of girls was critical to anti-poverty efforts and that the issue had not been sufficiently emphasized in the UN's previous Millennium Development Goals.
"When we look at investing our own money or asking governments to invest their money... we have to make sure that those investments make a difference," she said.
Read: Modi to visit Facebook headquarters in US: Zuckerberg
For a girl, "for every year she is educated, she increases her income by 20 per cent when she goes out to get a job," Gates said.
Gates said that family planning was also "hugely important" to fighting poverty by ensuring that parents can adequately provide for children.
But Margaret Chan, head of the World Health Organization, acknowledged that cultural factors posed a challenge to helping girls.
"Many of the issues that affect women and girls are not talked about -- violence against women -- and this is not only in developing countries," she said.
COMMENTS (1)
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ