The 19-year-old tore Argentina apart in one of the games of the World Cup on Saturday, scoring twice in France's 4-3 win.
The performance marked something of a changing of the guard, with Lionel Messi eliminated from the tournament and Mbappe soaring into the quarter-finals, where Les Bleus will play Uruguay.
And Mbappe has now been compared to 'O Fenomono' by Real Madrid defender Varane, who believes the teenager has yet to reach his full potential.
"Kylian has a lot of talent, speed and goals, but he's still very young," he told reporters, per Marca.
"He has qualities similar to Ronaldo, the Brazilian, but he's also something different, he likes dribbling, he's learning and we're happy to have a player like him."
Mbappe moved to PSG at the beginning of the 2017-18 season, on an initial loan deal from Monaco, with the capital club eventually sealing the transfer for a staggering £166 million (€187m/$218m).
The attacker was something of a support act at Parc des Princes, however, as he supplemented the talents of Neymar.
He still managed to score 21 goals and provide 16 assists in 46 appearances, however, and speculation persists over whether Real will make a move to secure one of the finest young talents of this generation.
Varane, however, is remaining tight-lipped. Asked about the possibility of Mbappe joining him at Santiago Bernabeu, he replied: "He will triumph in whatever team he is on."