See main article: 2004 Kremlin Cup.
Defending champion Anastasia Myskina defeated Elena Dementieva in the final, 7–5, 6–0 to win the women's singles tennis title at the 2004 Kremlin Cup.
A champion seed is indicated in bold text while text in italics indicates the round in which that seed was eliminated. The top four seeds received a bye to the second round.
Lindsay Davenport (semifinals)
Anastasia Myskina (champion) Svetlana Kuznetsova (quarterfinals) Elena Dementieva (final) Vera Zvonareva (quarterfinals) Venus Williams (quarterfinals) Nadia Petrova (second round)