According to De Telegraaf (h/t Dutch football journalist Elko Born), the European champions are admirers of the Netherlands international, although they will likely face competition from Manchester United for the playmaker.
It's added that the Red Devils have already sent scouts to Ajax matches this term to run the rule over De Jong.
The clubs linked with De Jong are indicative of a player who has shown enormous promise early in his Ajax career.
Although he's not a product of the club's revered academy having joined from Willem II in 2015, the Dutchman boasts a lot of the traits you'd associate with the Amsterdam giants. He's technically excellent, versatile in where he can play and composed on the ball.
Having made his debut for Ajax in the 2016-17 campaign, De Jong went on to establish himself in the side last season as a central defender. So far this term he's been used in midfield for both club and country.
WhoScored.com summed up how at ease De Jong is when in possession:
Despite the interest from elite clubs across Europe in the summer the youngster stayed at Ajax and is set to play a crucial role in both the Dutch top flight and the UEFA Champions League.
Those minutes will be vital to De Jong's overall development. Despite his talent and sky-high potential he still has a lot to learn about the game at the highest level; playing in his preferred position and up against some of Europe's best in continental matches will help battle-harden this refined young player.
Still, if a team like Madrid, United, Barcelona or Tottenham were to make a massive offer for the midfielder, he would surely find that opportunity tough to turn down.
Rafael Hernandez of Barca fansite Grup14 believes he would be an ideal player to work under Pep Guardiola at Manchester City:
City have been linked with a January bid by the Mirror's Simon Mullock.
Madrid have outstanding options in central areas, with Luka Modric, Toni Kroos and Casemiro proving themselves as a formidable trio in recent years. Dani Ceballos is another option for Los Blancos in this area too, meaning minutes might be tough to come by if De Jong moved to the Spanish capital in the near future.
However, with Modric now 33 and Mateo Kovacic out on loan at Chelsea, the European champions may have to revamp this area of the team over the next few windows. De Jong would potentially be a building block in this side for years to come.