The 2018 IsarOpen was a professional tennis tournament played on clay courts. It was the 1st edition of the tournament which was part of the 2018 ATP Challenger Tour. It took place in Pullach, Germany between 6 August and 12 August 2018.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
| Jan-Lennard Struff | 56 | 1 | ||
 Czech Republic | Jiří Veselý | 89 | 2 | |
 Estonia | Jürgen Zopp | 96 | 3 | |
 Italy | Paolo Lorenzi | 110 | 4 | |
 Slovakia | Martin Kližan | 112 | 5 | |
 Norway | Casper Ruud | 138 | 7 | |
| Italy | Simone Bolelli | 144 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry into the singles main draw as special exempts:
The following players received entry from the qualifying draw:
The following players received entry as lucky losers:
See main article: 2018 IsarOpen – Singles.
See main article: 2018 IsarOpen – Doubles.
Sander Gillé / Joran Vliegen def. Simone Bolelli / Daniele Bracciali 6–2, 6–2.
