Edouard Philippe, the mayor of Le Havre, has been named France's prime minister by new president Emmanuel Macron.
The 46-year-old's appointment was announced in a short statement outside the Elysee palace on Monday.
His elevation to the role comes just hours after Mr Macron himself was inaugurated as France's new president on Sunday.
Replacing outgoing Francois Hollande, the 39-year-old took over the presidential reins during a high-security ceremony in Paris.
Mr Macron beat far-right wing candidate Marine Le Pen in the second round election run-off last week.
A former economy minister, he quit Mr Hollande's Socialist government last year to form his own centerist political movement, making him the first French president who does not represent one of the country's mainstream parties.