In a televised address to the nation, Mr Macron said efforts are needed as "the epidemic is accelerating".
"We're going to close nursery, elementary and high schools for three weeks," he said, adding that a nationwide 7pm-6am curfew will be kept in place.
"If we stay united in the coming weeks... then we will see light at the end of the tunnel," he said.
Restrictions already applying in the Paris region and others parts of north and eastern France will be extended to the whole country, for at least one month, Mr Macron announced.
Under these restrictions, people are allowed to go outside for leisure, but within a 10-kilometre radius from their homes - and without gathering.
Most non-essential shops are closed down.
The move is a departure from the government's policy in recent months, which has focused on regionalised restrictions.
School closures in particular had been seen as a very last resort.
However, the move comes as the country faces a rapid increase of patients in its hospitals.
The total number of Covid-19 patients in intensive care in France surged past 5,000 on Tuesday – the first time in 11 months that the figure has been that high.
Mr Macron said numbers of hospital ICU beds will be increased "in the coming days" from the current 7,000 to 10,000.
In total, France has reported more than 4.6 million cases of coronavirus and 95,495 Covid-related deaths.
A debate is scheduled in parliament on Thursday that will address the virus situation and the new measures.
"The key factor in our decision-making remains the situation in hospitals," government spokesman Gabriel Attal said on Wednesday after Mr Macron hosted his weekly coronavirus strategy meeting and a Cabinet meeting.
After Paris hospital officials warned they would have to start refusing needy patients for lack of space, he said, "One thing is clear: France will not refuse care for any sick patients. Choosing patients is not an option."
An overnight nationwide curfew has been in place since January, and all France's restaurants, bars, gyms, cinemas and museums have been closed since October.