| 1999 Estoril Open | |
|---|---|
| Date | 5–12 April |
| Edition | 10th (men) / 3rd (women) |
| Surface | Clay / outdoor |
| Location | Oeiras, Portugal |
| Champions | |
| Men's singles | |
 Albert Costa | |
| Women's singles | |
 Katarina Srebotnik | |
| Men's doubles | |
Tomás Carbonell /  Donald Johnson | |
| Women's doubles | |
| Alicia Ortuño / Cristina Torrens Valero | |
The 1999 Estoril Open was a tennis tournament played on outdoor clay courts at the Estoril Court Central in the Oeiras Municipality in Portugal that was part of the International Series of the 1999 ATP Tour and of Tier IVa of the 1999 WTA Tour. The tournament was held from 5 April until 12 April 1999. Albert Costa and Katarina Srebotnik won the singles title.