Williams leads active women with 13 Grand Slam titles, including three at Flushing Meadows. She recently won consecutive hard-court tuneup tournaments at Stanford and Toronto.

A former No. 1, the American is ranked 29th this week. That’s up from 175th in July, a few weeks after she returned to the tour following nearly a year off because of a series of health problems.

Top-ranked Caroline Wozniacki is seeded No. 1, followed by Vera Zvonareva. Two-time reigning US Open champion Kim Clijsters, who is ranked No. 3, will miss the tournament with a stomach muscle injury.