João Fonseca

About

Brazilian professional tennis player known for winning the 2023 US Open Boys' Singles Championship, for winning the 2025 Argentina Open and the 2025 Swiss Indoors Basel, and for becoming the first Brazilian since Gustavo Kuerten to win an ATP 500 title.

Before Fame

He started playing tennis when he was four years old at the Rio de Janeiro Country Club. He rose through the ranks as a junior player. He won the US Open Boys' Singles Title in 2023 and finished the year as the World No. 1 junior. He received a wildcard entry into the Rio Open in 2023. He earned his first ATP Tour victory in 2024 after he went pro. He won the Swiss Indoors Basel in October 2025.

Trivia

He became the first teenager since 2002 to beat a top 10 seed on his Grand Slam debut when he defeated Andrey Rublev at the 2025 Australian Open. 

Family Life

His full name is João França Guimarães Fonseca. His father Christiano Fonseca co-founded Brazil's first independent hedge fund and helped fund his budding tennis career as a child.

Associated With

He won the Swiss Indoors Basel in 2025, a tournament once dominated by his idol Roger Federer.