Supporters of French President Emmanuel Macron watch a screen in front of the Eiffel Tower as the first election projections are announced in Paris, France, Sunday, April 24, 2022. AP
Centrist Macron was set to win 57.0-58.5 percent of the vote compared with Le Pen on 41.5-43.0 percent, according to projections by polling firms for French television channels based on a sample of the vote count.
The result is narrower than the second-round clash in 2017, when the same two candidates met in the run-off and Macron polled over 66 percent of the vote.
The outcome, expected to be confirmed by official results overnight, caused immense relief in Europe after fears a Le Pen presidency would leave the continent rudderless following Brexit and the departure of German chancellor Angela Merkel.
Italian Prime Minister Mario Draghi called Macron's victory "great news for all of Europe".
EU president Charles Michel said the bloc can now "count on France for five more years" while commission chief Ursula von der Leyen rapidly congratulated him saying she was "delighted to be able to continue our excellent cooperation".
In a combative speech to supporters in Paris where she accepted the result but showed no sign of quitting politics, Le Pen, 53, said she would "never abandon" the French and was already preparing for June legislative elections.
"The result represents a brilliant victory," she said to cheers.
The relatively comfortable margin of victory gives Macron some confidence as he heads into a second five-year mandate, but the election also represents the closest the far-right has ever come to winning power in France.
Macron is the first French president to win re-election since Jacques Chirac in 2002 after his predecessors Nicolas Sarkozy and Francois Hollande left office after only one term.
The 44-year-old is to make a victory speech on the Champ de Mars in central Paris at the foot of the Eiffel Tower where flag-waving supporters erupted in joy when the projections appeared at 8:00 pm local time (1800 GMT).
- High ambitions -
Macron will be hoping for a less complicated second term that will allow him to implement his vision of more pro-business reform and tighter EU integration after a first term shadowed by protests, then the pandemic and finally Russia's invasion of Ukraine.
But he will have to win over those who backed his opponents and the millions of French who did not bother to vote.
On the basis of the official figures, polling organisations estimated that the abstention rate was on course for 28 percent which, if confirmed, would be the highest in any presidential election second-round run-off since 1969.
The outcome of the first round on April 10 had left Macron in a solid but not unassailable position to retain the presidency.
Convincing supporters of the hard-left third-placed candidate Jean-Luc Melenchon to hold their noses and vote for the former investment banker was a key priority for Macron in the second phase of the campaign.
Macron will also need to ensure his party finds strong grassroots support to keep control of a parliamentary majority in the legislative elections in June and avoid any awkward "cohabitation" with a premier who does not share his political views.
- Bitter pill for Le Pen -
High on his to-do-list is pension reform including a raising of the French retirement age which Macron has argued is essential for the budget but is likely to run into strong opposition and protests.
He will also have to rapidly return from the campaign trail to dealing with the Russian onslaught against Ukraine, with pressure on France to step up supplies of weapons to Kyiv and signs President Vladimir Putin is losing interest in any diplomacy.
For Le Pen, her third defeat in presidential polls will be a bitter pill to swallow after she ploughed years of effort into making herself electable and distancing her party from the legacy of its founder, her father Jean-Marie Le Pen.
Critics insisted her party never stopped being extreme-right and racist while Macron repeatedly pointed to her plan to ban the wearing of the Muslim headscarf in public if elected.
When Jean-Marie Le Pen reached the second round in 2002, the result stunned France and he won less than 18 percent in the subsequent run-off against Chirac.