Joost Klein, also known mononymously as Joost, is a Dutch musician, rapper, singer, and former RU-vidr. Mainly a hip hop artist, his songs and performances often include influences of electronic music, such as drum and bass, hardstyle, and gabber. He has released eight studio albums, two of which reached the top ten of the Dutch Album Top 100. He has amassed four chart entries on the Dutch Top 40, and is best known for "Wachtmuziek", "Europapa", Luchtballon and his collaborations with German rapper Ski Aggu on "Friesenjung" and Finnish rapper Käärijä on "Trafik!".
"Europapa" was selected to represent the Netherlands in the Eurovision Song Contest 2024 and subsequently became Klein's first song to top both the Dutch Top 40 and Single Top 100. Having qualified from the semi-final, he was scheduled to perform fifth in the final, but was disqualified from the competition amidst allegations of misconduct. The allegations were investigated by Swedish prosecutors, who dropped the case in August 2024 after concluding that they could not prove any criminal conduct.