Otto Virtanen (born 21 June 2001) is a Finnish professional tennis player who reached a career-high ATP singles ranking of No. 91 in November 2024 and is currently the top-ranked singles player from Finland. He first gained attention as a junior by winning the Boys' Doubles title at Wimbledon in 2018 and the prestigious Orange Bowl singles tournament that same year. Virtanen's professional breakthrough came in 2024 when he made his Grand Slam debuts at the French Open and Wimbledon, secured his first Major wins, and lifted his sixth Challenger title in Brest, France, to crack the top 100 on 28 October 2024. He notably became just the tenth player in Challenger history to win his first six final appearances, a feat last achieved by Alexander Bublik in 2019. In 2025, he made his Masters 1000 debut in Rome and recorded his first win there, while also defeating top-30 player Sebastian Korda in Marseille. His most significant victory came at the 2026 Wimbledon Championships, where he defeated world No. 5 Ben Shelton in five sets, becoming the first Finnish ATP player in the Open Era to beat a top-five seed at a Major.