The Prime Minister, who is currently on holiday in Lake Garda, Italy, will make the short trip to the south of France for talks with Mr Macron.
The leaders are expected to meet at Fort Bregancon near Toulon on Friday evening to thrash out details of the UK’s exit from the EU.
Their hastily organised summit will be followed by a private dinner between Mr Macron and Mrs May and their respective partners.
Mr Macron and Mrs May last came face-to-face at the Nato summit in Brussels earlier this month.
But the Government is keen to step up its engagement with leaders on the continent as Brexit edges closer.
Mrs May has met with other EU leaders including German Chancellors Angela Merkel and Austria’s Sebastian Kurz in recent weeks.
The talks on Friday will are expected to focus Mrs May’s Brexit plan agreed by the Cabinet at Chequers earlier this month.
Leading Cabinet Brexiteers David Davis and Boris Johnson resigned in protest at the proposal, plunging the Government into chaos.
Foreign Secretary Jeremy Hunt travelled to Paris earlier today to discuss Brexit with his French counterpart Jean-Yves Le Drian.
Speaking to reporters, Mr Hunt urged EU negotiators to support Britain’s proposals for a “pragmatic and sensible” outcome.
The Cabinet big-hitter also claimed the likelihood of Britain crashing out of the EU without a deal is “increasing by the day”.
He said: “There is real chance of no deal by accident. Everyone is assuming, ‘No this will never happen’. Well, actually, it could.
“We need a change of approach from the European Commission, who have this view that they just need to wait and Britain will blink.
“That is just a profound misunderstanding of us as a nation.
“We need to negotiate a pragmatic and sensible outcome that protects jobs on both sides of the Channel.”
Emmanuel Macron, a staunch Europhile, is understood to be pursuing a hardline stance against the UK in Brexit negotiations.
The French leader and his allies have rejected a number of compromises put forward by British officials, according to Brussels sources.
An EU diplomat told Express.co.uk: “Do you know the country blocking the most compromises? France, they are the toughest on the UK.
“They block most of the offers brought to the table by the UK, they allow no compromises.”
The surprise meeting was announced by Elysee Palace sources this afternoon before being confirmed by Downing Street.
A No10 spokeswoman said: “We can confirm the PM will be travelling to France to meet President Macron after her holiday on Friday.”