French far-right leader Marine Le Pen was - as perhaps could have been expected given the result - the quickest off the blocks to react to the referendum result in the UK.
The far-right national front leader hailed Britain's decision to leave the European Union and called for a similar referendum in France.
"Victory for Freedom! As I have been asking for years we must now have the same referendum in France and EU countries," the National Front (FN) leader tweeted.
The eurosceptic, anti-immigration FN has accused the EU of suffering a "democratic deficit" and has long urged all members of the bloc to follow Britain's example.
Fears are high that a domino effect could see other countries following in Britain's footsteps, threatening the core of the European project.
Within the French government, it was the Foreign Minister Jean-Marc Ayrault who the first to react.
He bemoaned Britain's "sad" decision to leave the EU, saying Europe must win back the trust of its people.
"Sad for the United Kingdom. Europe carries on but it must react and win back the trust of its people. It is urgent," he tweeted.
Triste pour le Royaume-Uni. L'Europe continue mais elle doit réagir et retrouver la confiance des peuples. C'est l'urgence.— Jean-Marc Ayrault (@jeanmarcayrault) June 24, 2016
The French Prime Minister Manuel Valls said: "We must respect the decision of the British voters", a sentiment echoed by Paris Mayor Anne Hidalgo, who nevertheless described it as a "sad day for Europe".
The mayor however vowed to continue building links between the UK and France.
French President Francois Hollande, fresh from an emergency ministerial meeting on Friday to discuss the impact of the referendum, said the Brexit vote would be a "grave test for Europe".
He had warned that Brexit would "have extremely serious consequences".
"It's more than the future of the United Kingdom that is at stake, it's the future of the European Union," Hollande said on Wednesday.
He will have the task, along with Angela Merkel of uniting the rest of Europe to persuade other countries from steering away from the path that the UK has taken.
The French President has suggested in the past that the eurozone must push for greater cooperation to boost the competitiveness of the bloc.