2021 Oeiras Ladies Open

The 2021 Oeiras Ladies Open was a professional women's tennis tournament played on outdoor clay courts. It was the first edition of the tournament which was part of the 2021 ITF Women's World Tennis Tour. It took place in Oeiras, Portugal between 12 and 18 April 2021.

Seeds

 * 1 Rankings are as of 5 April 2021.

Other entrants
The following players received wildcards into the singles main draw:
 * 🇧🇷 Beatriz Haddad Maia
 * 🇺🇦 Elizabet Hamaliy
 * Francisca Jorge
 * Inês Murta
 * Ana Filipa Santos

The following player received entry using a protected ranking:
 * 🇷🇴 Alexandra Dulgheru

The following player received entry using a junior exempt:
 * 🇦🇩 Victoria Jiménez Kasintseva

The following player received entry using as a special exempt:
 * 🇮🇹 Lucia Bronzetti

The following players received entry from the qualifying draw:
 * 🇮🇹 Federica Di Sarra
 * 🇩🇪 Sina Herrmann
 * 🇰🇷 Jang Su-jeong
 * Suzan Lamens
 * 🇫🇷 Diane Parry
 * 🇪🇸 Olga Sáez Larra
 * 🇺🇸 Katie Volynets
 * 🇩🇪 Stephanie Wagner

The following player received entry as a lucky loser:
 * 🇪🇸 Marina Bassols Ribera

Singles

 * Polona Hercog def. 🇫🇷 Clara Burel, walkover

Doubles

 * 🇧🇾 Lidziya Marozava / 🇷🇴 Andreea Mitu def. 🇷🇺 Marina Melnikova / Conny Perrin, 3–6, 6–4, [10–3]