Founded in 1899, the Cincinnati Open is the oldest tennis tournament in the United States still staged in or near its original city — older than the modern majors that surround it on the calendar. It spent its early decades on clay under the Tri-State Tennis Tournament banner before the switch to hard courts that fixed its modern identity. Today it runs as a combined Masters 1000 / WTA 1000 event across nearly two weeks of mid-August, the marquee dates running 13–24 August in 2026.
The slot is the whole identity. Cincinnati is the last full-scale 1000-level stop before the US Open, the closing test of a North American hard-court swing that begins with the Canadian Open. Midwest August heat and humidity make the venue a physical gauntlet — fast, low-bouncing hard courts under brutal sun, where stamina is as much a selector as ball-striking. A deep Cincinnati run reads as a credential heading into Flushing Meadows.
The recent champions trace the current order. Carlos Alcaraz took the 2025 men's title when Jannik Sinner retired in the final — there is no full scoreline because the match ended in retirement. A year earlier, Sinner himself lifted the trophy, edging Frances Tiafoe 7-6, 6-2. On the women's side, Coco Gauff won the 2023 final over Karolina Muchova 6-3, 6-4 — a springboard to her breakthrough US Open run weeks later.
That Gauff sequence is the Cincinnati pattern in miniature: the event functions as a proving ground where late-August form converts directly into Grand Slam stakes. The combined format keeps both tours under one roof at the same site, making it one of the highest-density 1000-level draws of the year — and the last place contenders can audition before the season's final major.