Kateřina Siniaková became the ninth woman in the Open Era to complete the career Grand Slam twice at the 2026 US Open.
Siniaková achieved the milestone by winning the women’s doubles title with Taylor Townsend. Their victory completed the set of four major women’s doubles titles for the partnership, while Siniaková had already completed a career Grand Slam with Barbora Krejčíková.
A career Grand Slam means winning the Australian Open, French Open, Wimbledon and US Open during a player’s career. In doubles, the achievement is tracked for the player rather than requiring the same partner at every tournament. That distinction explains why Siniaková could complete the feat twice with two different teammates.
Townsend also completed her first career Grand Slam with the victory. The final ended 5–7, 6–0, 6–2 against Ashlyn Krueger and Robin Montgomery, giving Siniaková and Townsend the No. 1-seeded championship.