The 2005 Estoril Open was a tennis tournament played on outdoor clay courts. This event was the 16th edition of the Estoril Open for the men (the 9th for the women), included in the 2005 ATP Tour International Series and in the 2005 WTA Tour Tier IV Series. Both the men's and the women's events took place at the Estoril Court Central, in Oeiras, Portugal, from 25 April through 1 May 2005. Gastón Gaudio and Lucie Šafářová won the singles titles.

Finals

Men's singles

🇦🇷 Gastón Gaudio defeated 🇪🇸 Tommy Robredo, 6–1, 2–6, 6–1

Women's singles

🇨🇿 Lucie Šafářová defeated Li Na, 6–7(4–7) 6–4, 6–3

Men's doubles

🇨🇿 František Čermák / 🇨🇿 Leoš Friedl defeated 🇦🇷 Juan Ignacio Chela / 🇪🇸 Tommy Robredo, 6–3, 6–4

Women's doubles

Li Ting / Sun Tiantian defeated Michaëlla Krajicek / 🇸🇰 Henrieta Nagyová, 6–3, 6–1