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, and she became the first Canadian, as well as the first player born in the 2000s, to win a major singles title. She was the youngest player since Svetlana Kuznetsova in 2004 to win the US Open title, and the first woman to win the US Open on her main draw debut. This was also the first time a player won a title on their debut appearance at a Grand Slam tournament since Monica Seles won the 1991 Australian Open. In addition, Andreescu tied Seles’ Open Era record of fastest path from Grand Slam debut to winning a title, winning at her fourth ever grand slam appearance. This was also the largest age gap (18 years) between the finalists in a women’s Grand Slam final 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.
It marked the first time in history that the tournament's draw included eight 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, 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). Williams was attempting to equal Margaret Court's all-time record of 24 major singles titles, and to win an Open Era record seventh US Open title.
Despite losing in the fourth round, Ashleigh Barty regained the world No. 1 ranking from Osaka. In addition to Barty and Osaka, Karolína Plíšková and Simona Halep were also in contention for the top ranking.
Seeds.
Seeding per WTA rankings.
"Click on the seed number of a player to go to their draw section."
Draw.
Key.
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Championship match ratings.
3.219 million watched on ESPN in the US.
In Canada, preliminary data from Numeris showed a combined average audience of 3.4 million viewers on TSN and RDS, in English and French, respectively. Canadian viewership peaked at 5.3 million viewers at 5:59pm during the second set.
References.
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