In a tweet, Donald Trump said: "Congratulations to Emmanuel Macron on his big win today as the next President of France. I look very much forward to working with him."
A White House statement praised Mr Macron and the French people for "their successful presidential election" and said the United States looks forward to "continuing our close relationship with the French government".
Jubilant supporters of Macron in London hugged each other as the banker's figure beamed on to a screen, confirming him as the next French president.
Campaigners and voters for his En Marche movement, gathered at a central London pub, were tense with anticipation in the minutes running up to the result.
Within seconds of the exit poll being revealed, many were tweeting their joy at the victory of France's youngest candidate to win the presidency.
Student Arjun Alim, 20, said: "I'm absolutely thrilled, I think it's brilliant for France and Britain.
"It's finally time for someone other than a right-wing populist to take the stand."