William Rejchtman Vinciguerra (born 10 February 2007) is a Swedish tennis player. He has a career-high ATP singles ranking of No. 952 achieved on 30 March 2026 and a doubles ranking of No. 1,299 achieved on 16 March 2026.
He started playing tennis at a young age and was coached by his father Robert, as well as Thomas Högstedt, who previously trained Maria Sharapova and Caroline Wozniacki. In January 2023, he received a scholarship from The Streber Foundation.
As a junior, he reached the final of the Tennis Europe Masters Finals in Monaco, where he was defeated by Norwegian Nicolai Budkov Kjær.
He made his junior Grand Slam debut at the 2024 Australian Open. He competed in the junior events at the 2024 Wimbledon Championships where he also practised with Swedish ice hockey player William Nylander.
With Leo Borg, he was awarded a wildcard into the men's doubles at the 2024 Swedish Open for his ATP main draw debut.
His uncle is former professional tennis player Andreas Vinciguerra.