2018 Open Castilla y León

The 2018 Open Castilla y León was a professional tennis tournament played on outdoor hard courts. It was the 33rd edition, for men, and 4th edition, for women, of the tournament and part of the 2018 ATP Challenger Tour and the 2018 ITF Women's Circuit. It took place in El Espinar, Segovia, Spain, between 30 July – 5 August 2018.

Men's singles main draw entrants

The following players received wildcards into the singles main draw:

The following players received entry from the qualifying draw:

The following player received entry as a lucky loser:

¹ Rankings as of 23 July 2018.

The following players received wildcards into the singles main draw:

The following players received entry by special exempts:

The following players received entry from the qualifying draw:

Ugo Humbert def. Adrián Menéndez Maceiras 6–3, 6–4.

Liudmila Samsonova def. Başak Eraydın, 6–2, 6–0

Andrés Artuñedo / David Pérez Sanz def. Matías Franco Descotte / João Monteiro 6–7, 6–3, .

Marina Bassols Ribera / Olga Parres Azcoitia def. Tamara Čurović / Başak Eraydın, 7–5, 6–4