Paris Saint-Germain forward Mbappe, 24, accepted the role after discussions with coach Didier Deschamps.
His first game as captain will be Friday’s Euro 2024 qualifier against the Netherlands at the Stade de France, the first match for Les Bleus since the World Cup final in Doha on December 18.
Tottenham goalkeeper Lloris, 36, brought an end to his international career after Lionel Messi’s Argentina side beat the French in a penalty shootout after a thrilling match ended 3-3 following extra-time.
Lloris had been skipper for more than a decade.
Atletico Madrid attacker Antoine Griezmann was named vice-captain after Manchester United centre-back Raphael Varane also hung up his boots following the defeat to Argentina in December.
Mbappe, who scored a hat-trick in the World Cup final defeat, had been heavily linked with the captain’s role for weeks.
He helped Les Bleus to World Cup glory as a teenager in 2018 and has established himself as arguably the leading forward on the global stage.
The Paris-born former Monaco player is vice-captain at PSG behind Brazilian defender Marquinhos and led the side in the defender’s absence during Sunday’s loss to Rennes.
Mbappe has scored 19 goals in 24 Ligue 1 matches this season and contributed seven goals in PSG’s run to the last 16 of the Champions League, where they were knocked out by Bayern Munich
