The chart-topping singer arrived in the capital Dakar where she on Friday will join the Global Partnership for Education talks co-hosted by Senegalese President Macky Sall and French leader Emmanuel Macron.
Rihanna, the fourth most followed person on Twitter with 86 million followers, took to social media to urge Macron, British Prime Minister Theresa May and Australian Prime Minister Malcolm Turnbull to ensure specific funding levels.
In her tweet to Macron, Rihanna - who met with him in Paris in July - thanked the French leader for leading the conference but pressed him to commit firmly to 250 million euros ($313 million) for the effort.
Speaking to Turnbull, she urged funding as part of Australia's entry onto the UN Human Rights Council.
Some 264 million school-age children and youths are living without any education owing to poverty, conflict and social barriers including bias against girls, according to the United Nations Children's Fund.
The Dakar conference, which brings together governments and the private sector, aims to raise $3.1 billion over the coming three years to support education for 870 million children.
The conference in turn asks partner countries to devote 20 percent of public expenditure to education - a level that can be particularly difficult for countries battling jihadists or civil conflicts.
Rihanna, who serves as an ambassador for the Global Partnership for Education, will meet in Dakar with government officials as well as educators and students, representatives said.
She has frequently been active in pressing for development funding as part of Global Citizen, the anti-poverty campaign that includes policy events and concerts in New York and a growing number of other cities.
The Barbados-born singer - whose hits include 'Diamonds' and 'Only Girl (In the World' - has also set up the non-profit Clara Lionel Foundation, which includes a scholarship fund for students to learn at US universities.
With her Twitter account, she has repeatedly approached leaders including Canadian Prime Minister Justin Trudeau to raise development issues.
