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.
| Country | Player | Rank | Seed | |
|---|---|---|---|---|
| Anke Huber | 30 | 1 | ||
 France | Sarah Pitkowski | 43 | 2 | |
 Luxembourg | Anne Kremer | 44 | 3 | |
| Elena Wagner | 77 | 4 | ||
| Silvija Talaja | 81 | 5 | ||
 Belarus | Olga Barabanschikova | 82 | 6 | |
 Italy | Laura Golarsa | 89 | 7 | |
| Seda Noorlander | 91 | 8 |
The following players received wildcards into the singles main draw:
The following players received wildcards into the doubles main draw:
The following players received entry from the singles qualifying draw:
The following players received entry as a lucky loser:
The following player received entry from the doubles qualifying draw:
See main article: 1999 Estoril Open – Men's singles. 
Albert Costa defeated 
Todd Martin, 7–6(7–4), 2–6, 6–3
See main article: 1999 Estoril Open – Women's singles. Katarina Srebotnik defeated 
Rita Kuti-Kis, 6–3, 6–1
See main article: 1999 Estoril Open – Men's doubles. Tomás Carbonell / Donald Johnson defeated 
Jiří Novák / David Rikl, 6–3, 2–6, 6–1
See main article: 1999 Estoril Open – Women's doubles. Alicia Ortuño / Cristina Torrens Valero defeated Anna Földényi / Rita Kuti-Kis, 7–6(7–4), 3–6, 6–3
