The UK will increase its contribution to global education by 50%, helping more than 800,000 children stay in school.
International Development Secretary Penny Mordaunt is announcing Britain's support for the Global Partnership for Education at an international conference in Senegal.
She is promising £225 million over the next three years at the event in Dakar, hosted by France's President Emmanuel Macron and Senegal's President Macky Sall.
The UK's support will aim to keep 880,000 children in school for three years, build 2,400 classrooms and train 170,000 teachers.
Although 89% of children are in school, many leave without basic literacy and numeracy skills because teachers lack knowledge or equipment.
Speaking at the event on Friday, Ms Mordaunt said: "It's a terrible waste of potential that half the world's children leave primary school unable to read or write because the quality of teaching is so poor.
"We need an education revolution, but to succeed in tackling this global learning crisis, we will not just need to be open-hearted, we need to be hard-headed too."
While there, she met pop singer Rihanna, who is a global ambassador for education.
Ms Mordaunt said the UK will "lead the way" in helping over governments improve their education systems.