Most Semifinals at Single Tournament

At the top of the Open Era list for Most Semifinals at a Single Tournament stands 🇨🇭 Roger Federer, who reached the semifinals of Basel / Swiss Indoors 16 times — the highest known men’s singles total at one tour-level event. Federer also reached the semifinals 16 times at the ATP Finals. He reached a record 15 Basel finals and also lost in the 2002 Basel semifinal to 🇦🇷 David Nalbandian, giving him 16 total semifinal-or-better appearances at his hometown tournament.

Behind him, the strongest Grand Slam benchmarks are 🇪🇸 Rafael Nadal at Roland Garros and 🇨🇭 Roger Federer at the Australian Open, both with 15 semifinals. Nadal went 14-1 in Roland Garros semifinals and ultimately won 14 titles there.

Another tour-level reference is 🇨🇭 Roger Federer at Halle, where he reached the semifinals 15 times, while the Masters 1000 benchmark is Monte-Carlo, where Nadal reached the semifinals 14 times.

In this record, the milestone is not simply winning the title, but repeatedly surviving to the final four at the same event: Federer set the overall single-tournament ceiling with 16 Basel semifinals, Nadal and Federer share the Grand Slam version with 15 semifinals at Roland Garros and the Australian Open, and Monte-Carlo provides the Masters 1000 benchmark through Nadal.