2004 Estoril Open – Women's singles

Magüi Serna was the defending champion, but did not compete this year.

Émilie Loit won the title by defeating Iveta Benešová 7–5, 7–6(7–1) in the final. It was the 2nd title in the year for Loit and the 8th title in her singles career.

Seeds
• # 🇷🇺 Elena Bovina (second round)

• # 🇦🇺 Alicia Molik (first round)

• # 🇫🇷 Émilie Loit (champion)

• # 🇨🇿 Denisa Chládková (quarterfinals)

• # 🇦🇹 Barbara Schett (quarterfinals)

• # 🇨🇿 Iveta Benešová (final)

• # Katarina Srebotnik (second round)

• # 🇫🇷 Marion Bartoli (first round)