2008 US Open – Women's singles

Serena Williams defeated Jelena Janković in the final, 6–4, 7–5 to win the women's singles tennis title at the 2008 US Open. It was her third US Open singles title and ninth major singles title overall. This was also her second US Open and third major overall won without losing a set during the tournament. With the win, she regained the world No. 1 singles ranking for the first time since 2003. Three of the top four seeds were in contention for the No. 1 ranking at the start of the tournament.

Justine Henin was the reigning champion, but retired from the sport in May 2008.

This was the final singles major appearance for 1998 champion and former world No. 1 Lindsay Davenport, who was defeated by Marion Bartoli in the third round.

Julie Coin, ranked as the world No. 188, defeated the world No. 1 Ana Ivanovic in the second round, making her the lowest-ranked player ever to defeat a world No. 1.

Seeds
• 🇷🇸 Ana Ivanovic (second round)

• 🇷🇸 Jelena Janković (final)

• 🇷🇺 Svetlana Kuznetsova (third round)

• 🇺🇸 Serena Williams (champion)

• 🇷🇺 Elena Dementieva (semifinals)

• 🇷🇺 Dinara Safina (semifinals)

• 🇺🇸 Venus Williams (quarterfinals)

• 🇷🇺 Vera Zvonareva (second round)

• 🇵🇱 Agnieszka Radwańska (fourth round)

• 🇷🇺 Anna Chakvetadze (first round)

• 🇸🇰 Daniela Hantuchová (first round)

• 🇫🇷 Marion Bartoli (fourth round)

• 🇭🇺 Ágnes Szávay (second round)

• 🇧🇾 Victoria Azarenka (third round)

• Patty Schnyder (quarterfinals)

• 🇮🇹 Flavia Pennetta (quarterfinals)

• 🇫🇷 Alizé Cornet  (third round)

• 🇸🇰 Dominika Cibulková (third round)

• 🇷🇺 Nadia Petrova (third round)

• 🇨🇿 Nicole Vaidišová (second round)

•  Caroline Wozniacki (fourth round)

• 🇷🇺 Maria Kirilenko (first round)

• 🇺🇸 Lindsay Davenport (third round)

• 🇮🇱 Shahar Pe'er (first round)

• 🇮🇹 Francesca Schiavone (second round)

• 🇪🇸 Anabel Medina Garrigues (second round)

• 🇺🇦 Alona Bondarenko (third round)

•  Katarina Srebotnik (fourth round)

• 🇦🇹 Sybille Bammer (quarterfinals)

• 🇯🇵 Ai Sugiyama (third round)

• 🇫🇷 Virginie Razzano (first round)

• 🇫🇷 Amélie Mauresmo (fourth round)