| Champ: |  Kim Clijsters |
| Runner: | Caroline Wozniacki |
| Score: | 7–5, 6–3 |
| Before Name: | US Open – Women's singles |
| After Name: | US Open – Women's singles |
See main article: article and 2009 US Open (tennis).
Kim Clijsters defeated Caroline Wozniacki in the final, 7–5, 6–3 to win the women's singles tennis title at the 2009 US Open. It was her second US Open title and her second major singles title overall. She became the first unseeded player and wild card to win the title, and the first mother to win a major since Evonne Goolagong in 1980. Following her win, she appeared at 19th in the rankings. This was the first time since the 2007 Australian Open where Clijsters participated in a major, as she was contesting just her third tournament since coming out of retirement.
Serena Williams was the defending champion, but was defeated in the semifinals by Clijsters. A foot fault was called for Williams at the end of the second set, producing two match points for Clijsters. Williams argued the call and was given a point penalty for intimidating a line judge, ending the match (having already had a warning for racquet abuse earlier in the match).[1]
Svetlana Kuznetsova's loss in the fourth round guaranteed a first time major finalist from the top half of the draw. Wozniacki became the first Danish woman to reach a major final, and the first Scandinavian to reach the final since Molla Bjurstedt Mallory in 1918.[2]
This was the final major appearance for two-time major champion Amélie Mauresmo, who lost to Aleksandra Wozniak in the second round. This was also the final major singles appearance of Ai Sugiyama, who was on a record-breaking 62nd consecutive major singles appearance, losing in the first round to Samantha Stosur. Sugiyama's record was eventually broken by Alizé Cornet in 2022.
See also: 1 and 1. 
Dinara Safina (third round)
See also: 2 and 8. 
Serena Williams (semifinals)
See also: 3 and 6. Venus Williams (fourth round)
See also: 4 and 3. Elena Dementieva (second round)
See also: 5 and 2. 
Jelena Janković (second round)
See also: 6 and 4. Svetlana Kuznetsova (fourth round)
See also: 7 and 7. Vera Zvonareva (fourth round)
See also: 8 and 5. 
Victoria Azarenka (third round)
See also: 9 and 4. Caroline Wozniacki (final)
See also: 10 and 7. 
Flavia Pennetta (quarterfinals)
See also: 11 and 2. Ana Ivanovic (first round)
See also: 12 and 5. 
Agnieszka Radwańska (second round)
See also: 13 and 3. Nadia Petrova (fourth round)
See also: 14 and 6. 
Marion Bartoli (second round)
See also: 15 and 8. 
Samantha Stosur (second round)
See also: 16 and 1. Virginie Razzano (first round)
See also: 17 and 7. Amélie Mauresmo (second round)
See also: 18 and 5. 
Li Na (quarterfinals)
See also: 19 and 1. Patty Schnyder (second round)
See also: 20 and 6. 
Anabel Medina Garrigues (second round)
See also: 21 and 3. Zheng Jie (third round)
See also: 22 and 8. 
Daniela Hantuchová (fourth round)
See also: 23 and 2. Sabine Lisicki (second round)
See also: 24 and 4. 
Sorana Cîrstea (third round)
See also: 25 and 6. 
Kaia Kanepi (first round)
See also: 26 and 5. Francesca Schiavone (fourth round)
See also: 27 and 1. Alisa Kleybanova (first round)
See also: 28 and 8. 
Sybille Bammer (first round)
See also: 29 and 3. Maria Sharapova (third round)
See also: 30 and 2. 
Alona Bondarenko (second round)
See also: 31 and 7. Elena Vesnina (third round)
See also: 32 and 4. 
Ágnes Szávay (first round)
See main article: article and 2009 US Open – Women's singles qualifying.
| Category | Clijsters | Wozniacki | |
|---|---|---|---|
| 1st serve % | 53/85 (62%) | 43/63 (68%) | |
| 1st serve points won | 33 of 53 = 62% | 23 of 43 = 53% | |
| 2nd serve points won | 15 of 32 = 47% | 6 of 20 = 30% | |
| Total service points won | 48 of 85 = 56.47% | 29 of 63 = 46.03% | |
| Aces | 3 | 0 | |
| Double faults | 2 | 3 | |
| Winners | 36 | 10 | |
| Unforced errors | 34 | 21 | |
| Net points won | 11 of 15 = 73% | 9 of 15 = 60% | |
| Break points converted | 5 of 8 = 63% | 3 of 12 = 25% | |
| Return points won | 34 of 63 = 54% | 37 of 85 = 44% | |
| Total points won | bgcolor=98FB989 | 82 | 66 |
| Source | |||