Edouard Philippe, the 46-year-old Mayor of Le Havre, is a member of the Les Républicains party and is close to Alain Juppé, the former Prime Minister who endorsed Macron after he won the first round of the presidential election.
Emmanuel Macron sworn in as French president
At a press conference following the announcement Monday, Philippe thanked his predecessor, the Socialist Bernard Cazeneuve, and said: "You said you were a left-wing man, I have never doubted that. I am a right-wing man, you will not be surprised. Yet, we do respect each other and both know as you do that the general interest has to come first."
The choice of Philippe -- widely predicted by political pundits -- indicates Macron's desire to draw support from the conservative opposition and create balance, according to Emmanuelle Schön-Quinlivan, lecturer in European politics at University College, Cork, in Ireland.
Strong mandate sought
"Macron needs to retilt the people around him to the right as at the moment the main people around him are from the left. He needs to give a sign towards Les Républicains. This will be a sign to their followers that this government is genuinely from the left and the right," she told CNN.
Macron, the youngest French President in history at 39, is counting on winning votes from center-right supporters in elections for the National Assembly next month. His party, En Marche!, is scrambling to get 577 candidates together to contest every seat in the country.
Although he won the May 7 election against National Front candidate Marine Le Pen with 66% of the vote, his party was only founded last year and has never held a single National Assembly seat. Macron needs to win a majority in the June vote to have the mandate to push his legislative agenda through.
If he manages to achieve that, the Prime Minister's role will be to see through the promised reforms to address unemployment in France
and boost the ailing economy.
Not a high profile politician
Philippe, a lawyer with experience working in the private sector, was born in Rouen and grew up in a left-wing environment. He was a socialist in his younger days before switching his allegiances to Les Républicains.
He has only been an MP for one term, serving in the National Assembly representing the constituency of Seine-Maritime in Normandy in northern France since 2012.
At 46, he is the second-youngest Prime Minister of France behind Laurent Fabius, the Socialist PM from 1984 to 1986, who was 37 when appointed.
Philippe has been Mayor of Le Havre, a port city in northern France since 2010.
Cazeneuve said of his successor: "We have personal, friendly bonds... We should give the best of our politics to our country. We should call for appeasement and for the gathering of our political forces."
But Le Pen said: "This is the sacred alliance of the old left and right wings that are united in their will to maintain at any cost the same austerity policies, the same submission to Brussels, the same massive immigration and the same laxity, that have already harmed France very badly."
PM and President are friends
Although the new PM has not been a high-profile politician in France, his appointment was no surprise to politics watchers.
"Although he had suggested that he wanted a woman, everyone expected Edouard Philippe," Schön-Quinlivan said. "Macron needs a Prime Minister who could deal with the parliament, and knows the ins and outs of how it works."
The President and his new PM are friends, according to CNN affiliate BFMTV, having met regularly since they first got to know each other at a dinner in 2011.
The next step for Macron will be to announce his new cabinet of 15 ministers. Later on Monday, he will meet German Chancellor Angela Merkel in Berlin