2003 Estoril Open
Date	7–13 April
Edition	14th (ATP) / 7th (WTA)
Surface	Clay / outdoor
Location	Oeiras, Portugal
Champions
Men's singles
Nikolay Davydenko
Women's singles
Magüi Serna
Men's doubles
Mahesh Bhupathi / Max Mirnyi
Women's doubles
Petra Mandula / Patricia Wartusch
← 2002 · Estoril Open · 2004 →

The 2003 Estoril Open was a tennis tournament played on outdoor clay courts at the Estoril Court Central in Oeiras in Portugal that was part of the International Series of the 2003 ATP Tour and of Tier IV of the 2003 WTA Tour. The tournament ran from 7 April until 13 April 2003. Nikolay Davydenko and Magüi Serna won the singles title.

Finals

Men's singles

Nikolay Davydenko defeated Agustín Calleri 6–4, 6–3

• It was Davydenko's 2nd title of the year and the 2nd of his career.

Women's singles

Magüi Serna defeated Julia Schruff 6–4, 6–1

• It was Serna's 1st title of the year and the 3rd of her career.

Men's doubles

Mahesh Bhupathi / Max Mirnyi defeated Lucas Arnold / Mariano Hood 6–1, 6–2

• It was Bhupathi's 1st title of the year and the 27th of his career. It was Mirnyi's 3rd title of the year and the 16th of his career.

Women's doubles

Petra Mandula / Patricia Wartusch defeated Maret Ani / Emmanuelle Gagliardi 6–7^(3–7), 7–6^(7–3), 6–2

• It was Mandula's 1st title of the year and the 4th of her career. It was Wartusch's 1st title of the year and the 7th of her career.