João Klauss

Klauss signed for his first European club in January 2017, when he moved to TSG Hoffenheim in Germany. He initially struggled with the cultural change. He played 17 matches and scored four goals for Hoffenheim II in the Regionalliga Südwest. He was loaned to HJK in March 2018. On 8 April, he scored in his debut in the Veikkausliiga against Ilves. On 8 January 2019, Klauss was loaned out to LASK until 30 June 2020. On 31 January 2022, Klauss joined Sint-Truiden on loan. Klauss joined Major League Soccer side St. Louis City SC in July 2022, following his loan at Sint-Truiden. He was the club's first designated player. On February 25, 2023, the opening match of the MLS season, Klauss scored the winning goal in a 3–2 victory over Austin FC, the first win in St. Louis's franchise history. At the end of the 2023 season, Klauss was tied with Nicholas Gioacchini for being the club's leading goal scorer, after scoring 10 goals. On June 14, 2025, Klauss scored the first hat trick in St. Louis City SC history in a home match against the Los Angeles Galaxy. Once again at the end of the 2025 season, Klauss was the club's leading goal scorer with 10 goals. On January 27, 2026, Saint Louis City SC announced that the club had received $2.375 million for Klauss in a trade with LA Galaxy.

As of match played 22 March 2026

João Klauss de Mello was born in Criciúma, Santa Catarina. He began his career with Internacional in Porto Alegre, joining the club at the age of nine. Klauss moved with his mother to Porto Alegre after his parents separated. Both parents supported his football career from early on. At the age of 13, he was released from Internacional's youth program and moved to Juventude in Caxias do Sul. After a year, he moved back to Porto Alegre and joined the Grêmio's youth academy.

Born in Brazil, Klauss is of German descent through his father, and Italian descent through his mother. He holds an Italian passport.