France opened the scoring just before half-time, as the new Real Madrid forward stood up a cross to Randal Kolo Muani, who sent a header into the bottom corner.
Les Bleus, naturally, dominated possession against the minnows but Luxembourg frustrated a strong frontline throughout the first period, and only headed into half-time one goal down.
It was a laboured display from the French throughout the first hour, with Didier Deschamps' men seeing plenty of the ball but having very little to show for it.
It took a stunner to give France some breathing space with 20 minutes to go, as Jonathan Clauss produced a thunderbolt from the edge of the box.
Luxembourg kept plugging away and hit the bar late on, as they came within an inch of shocking the World Cup finalists, but it was Mbappe who had the last word.
Having missed a host of chances, the new Real Madrid Galactico poked home Bradley Barcola's cross to add some sheen to the scoreline.
GOAL rates France's players from Stade Saint-Symphorien...