France's new President-elect Nicolas Sarkozy has called for unity after a bitterly-contested campaign.
The conservative won a clear victory over his socialist rival Segolene Royal, gaining 53% of the vote with a massive 85% turnout.
Mr Sarkozy said the French people had chosen change and he would use the mandate he had received to achieve it.
After the result was announced, there were minor clashes with protesters in Paris and some other cities.
Several hundred rioters in the Place de la Bastille threw bottles and stones at police, shouting "Sarko-fascist".
Two police officers were injured in Nantes, where 1,000 demonstrators turned violent. Arrests were made in half-a-dozen cities, but the violence soon subsided.
'Work and morality'
Mr Sarkozy, 52, the son of a Hungarian immigrant, won enemies as interior minister for his harsh condemnation of rioters during urban unrest two years ago.
Now set to take over from 74-year-old President Jacques Chirac, he struck a conciliatory tone in his victory speech.
"Above and beyond the political fight... for me there is only once France. I will be president of all the French," he said.
"France has given me everything, and now it is my turn to give back to France what France has given me," he said.
He said the US could count on France's friendship, but urged Washington to take a lead in the fight against climate change.
Toulouse was one of a number of cities hit by unrest
He called on North African nations to join Europe in a Mediterranean Union, saying that France intended to help Africa conquer disease, famine, poverty and war.
Mr Sarkozy said he believed deeply in European integration, but appealed to France's partners to understand the importance of social protection.
"[Voters] have chosen to break with the habits and the ideals of the past so I will rehabilitate work, authority, morality, respect, merit," he said.
After he finished speaking at his party headquarters, jubilant supporters sang a rousing rendition of the French national anthem.
Ms Royal is the first woman ever to have made it to the second round of a French presidential election.
Conceding defeat - the third in a row for France's Socialist Party - she thanked 17m French people for their votes, saying she could measure their sadness and their pain.
"I gave it all my energy, and will continue," she told supporters. "Something has risen up that will not stop."
She expressed the hope that "the next president of the Republic" would accomplish his mission at the service of all the French people.
Mr Sarkozy has promised to try to reform France to face the challenges of the 21st century, with putting the nation back to work at the top of his agenda.
He has pledged to bring unemployment down from 8.3% to below 5% by 2012.
He is also expected to bring forward policies to cut taxes and keep trains running during strikes, in the first 100 days after he takes office on 16 May.