In 1999, Courtois joined Racing Genk at the age of seven. In 2010, aged 18, Courtois played a key role in Genk's Belgian Pro League victory.
In 2011 he joined Chelsea for a reported £8 million, and was immediately loaned to Atlético Madrid, where he played three seasons. In 2018, Real Madrid signed him for £35 million from Chelsea, making him become La Liga's most expensive goalkeeper. Now, he's Real Madrid's first-choice goalkeeper!