South African President Cyril Ramaphosa said schools were closing for four weeks to limit the spread of the novel coronavirus, which he described as a storm hitting the country.
The school closing order comes a week after teachers unions urged authorities to close schools through August, citing the increase in coronavirus cases.
South Africa currently has the fifth-highest total of COVID-19 infections in the world, with more than 400,000.
Ramaphosa said the school closures begin Monday and classes will resume on August 24 for most students.
However, Ramaphosa said Grade 12 teachers and students will take only a one-week break, while students in Grade 7 will resume classes after two weeks.