| 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 | |
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.