See main article: 2009 Australian Open.
Serena Williams defeated Dinara Safina in the final, 6–0, 6–3 to win the women's singles tennis title at the 2009 Australian Open. It was her fourth Australian Open singles title and tenth major singles title overall. With the win, Williams regained the world No. 1 ranking.
Maria Sharapova was the reigning champion, but withdrew from the tournament due to a recurring shoulder injury.
This was also the first Australian Open to feature three Russian semifinalists, those being Safina, Vera Zvonareva and Elena Dementieva.
See main article: 2009 Australian Open – Women's singles qualifying.
| Category |  S. Williams |  Safina | |
|---|---|---|---|
| 1st serve % | 21/37 (57%) | 29/49 (59%) | |
| 1st serve points won | 20 of 21 = 95% | 15 of 29 = 52% | |
| 2nd serve points won | 10 of 16 = 63% | 6 of 20 = 30% | |
| Total service points won | 30 of 37 = 81.08% | 21 of 49 = 42.86% | |
| Aces | 4 | 3 | |
| Double faults | 0 | 5 | |
| Winners | 23 | 14 | |
| Unforced errors | 7 | 21 | |
| Net points won | 4 of 5 = 80% | 2 of 3 = 67% | |
| Break points converted | 5 of 6 = 83% | 1 of 1 = 100% | |
| Return points won | 28 of 49 = 57% | 7 of 37 = 19% | |
| Total points won | bgcolor=98FB989 | 58 | 28 |
| Source | |||