The U.S. Open mixed doubles field is getting crowded and has landed a Williams sister.Tournament organizers announced a slew of new teams, including Venus Williams and Alexander Bublik, who will join the boldface names that already signed up last week, including Aryna Sabalenka and Novak Djokovic, Iga Światek and Casper Ruud and Naomi Osaka and Kei Nishikori.In addition to Williams and Bublik, the Czech duo of Karolina Muchová and Jakub Menšík are on the list, as are Anna Kalinskaya and Lorenzo Musetti and Emma Navarro and Tommy Paul. Newlyweds Katie Boulter and Alex De Minaur have also signed up, as have the longtime married couple Elina Svitolina and Gaël Monfils.The list did not include Serena Williams, even though the Cincinnati Open, the last major tuneup for the U.S. Open, announced Monday that she and her sister, Venus, had accepted a wild card into the doubles tournament.As in 2025, mixed doubles is the headline event for what the U.S. Open calls Fan Week, which takes up the seven days before the main-draw singles competition of the year’s final Grand Slam begins.

It was wildly successful last year, attracting some 78,000 spectators over two days of competition and packing Arthur Ashe Stadium for the semifinals and finals. Errani and Vavassori picked up $1 million for their win, but the highest-profile pair of doubles specialists this year is joint men’s world No. 1 Henry Patten, who has been outspoken on ATP Tour plans to cut doubles draws from 2028, uniting with women’s No. 1 Kateřina Siniaková.The men’s world No. 1, Jannik Sinner, who is yet to enter, said during Wimbledon that he would not play the mixed doubles event without significant progress in negotiations between a cohort of top-10 ATP and WTA players and the organizers of the four majors about prize money and other forms of player compensation. Entry closes on Aug. 17. Come that deadline, the six teams on the entry list with the best combined singles ranking will receive direct entry.Eight more teams will receive wild-card entries, with tournament organizers basing the decision on a combination of quality and star appeal. Then two more will come through an eight-team qualifying event, new for this year, to make a field of 16. That event will have six direct entries by ranking and two wild cards.As for the other new entry hopefuls, reigning NCAA singles champions Reese Brantmeier and Michael Zheng have teamed up. Jeļena Ostapenko, a Grand Slam singles champion, has teamed up with Marcelo Arévalo, a doubles specialist. Gabriela Dabrowski and Harri Heliövaara will form another doubles-specialist pairing, joining Demi Schuurs and Julian Cash. Caty McNally, a Grand Slam doubles finalist who is resurrecting her singles career after injury battles, will play with Robert Cash, a doubles specialist.