Serena Williams returned to the US Open mixed doubles after a four-year absence, partnering with Carlos Alcaraz in the tournament held a week before the singles main draw at Flushing Meadows. The pair won their opening match against Lloyd Glasspool and Erin Routliffe 5-3, 4-1 on August 25, 2026 [1, 2, 3, 4]. Williams impressed by serving a 193.1 km/h (120 mph) ace in that round, energizing the crowd [2, 3, 5, 6, 7, 8]. Alcaraz, playing his first competitive match since a wrist injury sustained in April 2026, praised the experience. "I'm playing next to the one and only Serena Williams, so what else can I do? Just enjoy and try to do the things she told me to do," he said [1].

Williams and Alcaraz’s run ended in the mixed doubles quarter-finals the same day. They lost to Flavio Cobolli and Belinda Bencic 5-4 (7-4), 4-1. Cobolli commented, "Playing Serena and Carlos on Arthur Ashe is not easy. I was tired before the match, I'm tired now," while Bencic said, "I don't know how I landed on this court – to play Carlos and Serena is a great honour" [1, 2, 4, 5, 6].

The mixed doubles event, in its second year under a revamped format focused on attracting singles stars, began the US Open schedule as planned in late August 2026 [1, 2, 3, 5]. Williams, age 44, declined a singles wildcard and did not enter the singles main draw this year [4].

On August 26, the US Open organizers granted Serena and her sister Venus Williams, age 46, a wildcard for the women's doubles draw. The Williams sisters have won the US Open women's doubles title twice before, in 1999 and 2009, and this marks their ninth US Open doubles appearance [9, 10, 11, 7, 8]. Earlier this month, they played together at the Cincinnati Open but lost in the first round [9, 10, 11, 7, 8].

Venus Williams is also entered in the women's singles draw, which begins August 30, 2026 [9, 11]. Serena and Venus are expected to start their doubles campaign around September 3 or 4, 2026 [9, 10].

Serena first returned to competitive tennis at the Queen’s Club Championships in June 2026 following a break from the sport [1, 10, 7]. She holds 23 Grand Slam singles titles, but has focused recently on doubles and mixed doubles appearances [1, 2, 3, 7]. The US Open continues as one of the last major events of the tennis season with high anticipation around the Williams sisters' performance in doubles and Venus's singles run.