2019 US Open – Women's singles

Bianca Andreescu defeated Serena Williams in the final, 6–3, 7–5 to win the women's singles tennis title at the 2019 US Open. It was her first major title. Andreescu was the first Canadian, as well as the first player born in the 2000s, to win a major singles title. She was the youngest player to win the title since Svetlana Kuznetsova in 2004, and the first woman to win the US Open on her main draw debut. This was the first time a player won a major on their debut appearance since Monica Seles won the 1991 Australian Open. In addition, Andreescu tied Seles’ Open Era record of the shortest time from major debut to winning a title, winning on her fourth major appearance (a record broken just two years later by Emma Raducanu, who won on her second major appearance). The final was a rematch of the Canadian Open final four weeks prior, also won by Andreescu. This was the largest age gap (18 years) between two women's major finalists in the Open Era. With the win, Andreescu entered the top 5 in rankings for the first time.

Naomi Osaka was the defending champion, but lost to Belinda Bencic in the fourth round.

This marked the first time that the tournament's draw included eight former champions: Osaka, Sloane Stephens, Angelique Kerber, Serena Williams, Samantha Stosur, Maria Sharapova, Kuznetsova, and Venus Williams.

In reaching her 33rd and last career major final, Serena Williams set a new record for the longest gap between a player's first and last major final appearances, her first being twenty years prior at the 1999 US Open. She also equaled the record for the most match wins at the US Open, held by Chris Evert (101 wins).

Despite losing in the fourth round, Ashleigh Barty regained the world No. 1 singles ranking from Osaka. In addition to Barty and Osaka, Karolína Plíšková and Simona Halep were also in contention for the top ranking.

This tournament marked the first US Open appearance of future champion and world No. 1 Iga Świątek; she lost to Anastasija Sevastova in the second round. This tournament also marked the final US Open appearances of former world No. 1 and 2006 champion Sharapova and former world No. 2 and 2004 champion Kuznetsova. Both lost in the first round, to Serena Williams and Kristie Ahn, respectively.