2003 Estoril Open – Women's singles

Magüi Serna was the defending champion and successfully defended her title, by defeating qualifier Julia Schruff 6–4, 6–1 in the final.

Seeds
• # Katarina Srebotnik (second round)

• # 🇪🇸 Magüi Serna (champion)

• # 🇫🇷 Virginie Razzano (semifinals)

• # 🇮🇹 Rita Grande (first round, retired)

• # 🇸🇰 Henrieta Nagyová (second round, retired)

• # 🇨🇿 Klára Koukalová (first round)

• # 🇦🇹 Patricia Wartusch (first round)

• # 🇨🇿 Iveta Benešová (second round)

Qualifying seeds
• #

Qualifiers
• #

Lucky losers
• # 🇺🇦 Elena Tatarkova

• # 🇨🇿 Sandra Kleinová

• # 🇦🇷 Gisela Dulko

Protected ranking

 * 1) 🇪🇸 Anabel Medina Garrigues