Real Madrid issued their denial after Spanish sports dailies Marca and AS ran articles citing the posting.
"Given the information published ...regarding an alleged agreement between Real Madrid and PSG for the player Kylian Mbappe, Real Madrid would like to state that it is completely false," the club said in a statement on their website.
"Real Madrid has not made any offer to PSG or the player and condemns the spreading of this type of information."
With speculation rife that world player of the year Cristiano Ronaldo will soon leave Real, the Madrid club also on Monday denied a report that they had offered 310 million euros for Mbappe's Brazilian PSG strike partner Neymar.
PSG signed Mbappe on an initial year-long loan deal from AS Monaco last year with an option to buy after one season. That deal was reported to be worth 180 million euros.
Mbappe has so far scored three World Cup goals, including two in France 4-3 round-of-16 victory over Argentina. France face Uruguay in a quarter-final in Nizhny Novgorod on Friday.
(Reporting by Arjun Panchadar in Bengaluru)
