| Date: | 1–7 October |
| Edition: | 9th |
| Draw: | 32S / 16D |
| Surface: | Hard |
| Location: | Monterrey, Mexico |
| Champs: |  David Ferrer |
| Champd: | Marcelo Arévalo /  Jeevan Nedunchezhiyan |
The 2018 Monterrey Challenger was a professional tennis tournament played on hard courts. It was the ninth edition of the tournament which was part of the 2018 ATP Challenger Tour. It took place in Monterrey, Mexico from 1 to 7 October 2018.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
| Spain | Marcel Granollers | 104 | 1 | |
 Italy | Paolo Lorenzi | 113 | 3 | |
| Spain | Adrián Menéndez Maceiras | 121 | 4 | |
| Ivo Karlović | 137 | 5 | ||
| Spain | David Ferrer | 149 | 6 | |
 Austria | Gerald Melzer | 153 | 7 | |
| Spain | Pedro Martínez | 174 | 8 |
The following players received wildcards into the singles main draw:
The following player received entry into the singles main draw using a protected ranking:
The following players received entry from the qualifying draw:
Harrison Adams
Gonzalo Escobar
Pavel Krainik
Zsombor PirosThe following player received entry as a lucky loser:
See main article: 2018 Monterrey Challenger – Singles.
David Ferrer def. Ivo Karlović 6–3, 6–4.See main article: 2018 Monterrey Challenger – Doubles.
Jeevan Nedunchezhiyan def. Leander Paes / 
Miguel Ángel Reyes-Varela 6–1, 6–4.
