The Real Madrid goalkeeper completed the investment via NXTPLAY — a sports, media and technology platform headquartered in Madrid — with the decision ratified by Genk's General Assembly on Monday evening.
Courtois came through Genk's academy and represented the first team between 2009 and 2011 before joining Chelsea, establishing himself as one of the world's finest goalkeepers over the decade and a half that followed. He framed the investment in explicitly personal terms.
"This investment is like coming home," he said. "With this commitment, I want to help the club continue to grow and consolidate its sporting ambitions. From Limburg to the top of Europe."
The deal goes beyond a passive financial stake. NXTPLAY will take a seat on Genk's board of directors — a role expected to be filled by Courtois's business partner Gonzalo Vila, who performs the equivalent function at the platform's other football investments, French club Le Mans and Spanish side CD Extremadura, who will compete in the Primera RFEF next season.
Courtois emphasised the dual nature of the investment.
"I grew up here and have personally experienced the strength of this club. For that reason, this investment has not only strategic value for me, but also great symbolic significance."
Genk described the deal as the first external investment the club has received since restructuring its football operations into a separate entity earlier this year — a move designed to strengthen its strategic positioning in the European market.
The investment forms the first step in a broader capital increase programme, with the potential to generate up to €60m for the club over the coming years.
Genk have been one of Belgium's most consistent clubs and are well regarded for their academy, having produced numerous players who have gone on to significant careers across Europe.
The 34-year-old Belgium international has been at Real Madrid since 2018, helping the club to Champions League glory in 2022 before suffering a serious knee injury that kept him out for almost a year. He returned to first-team football this season and has continued to be a fixture between the posts at the Bernabéu.