Emmanuel Macron has decisively won the French presidential election, defeating far-right candidate Marine Le Pen to become the country's youngest president at 39, a report said.

Macron won by 66.06 per cent to 33.94 per cent, reported BBC.

Macron will also become the first president from outside the two traditional main parties since the modern republic's foundation in 1958.

"I want it to be a page of hope and renewed trust," he said.

Macron said he had heard "the rage, anxiety and doubt that a lot of you have expressed" and vowed to spend his five years in office "fighting the forces of division that undermine France".

He said he would "guarantee the unity of the nation and... defend and protect Europe."

Macron's supporters gathered in their thousands to celebrate outside the Louvre museum in central Paris and their new president later joined them.

In his speech to the crowd, he said: "Tonight you won, France won. Everyone told us it was impossible, but they don't know France."

"We have the strength, the energy and the will - and we will not give in to fear,” he added, noting that the task facing him and the country was enormous.