The 2019 Tilia Slovenia Open was a professional tennis tournament played on hard courts. It was the seventh edition of the tournament which was part of the 2019 ATP Challenger Tour. It took place in Portorož, Slovenia between 12 – 18 August 2019.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
| Aljaž Bedene | 91 | 1 | ||
 Italy | ||||
| Blaž Rola | 139 | 3 | ||
 Ukraine | Sergiy Stakhovsky | 142 | 4 | |
 Slovakia | Filip Horanský | 162 | 5 | |
 France | Constant Lestienne | 180 | 6 | |
 Russian Federation | Alexey Vatutin | 193 | 7 | |
| Russian Federation | Roman Safiullin | 219 | 8 | |
| Italy | Matteo Viola | 245 | 9 | |
| Russian Federation | Evgeny Karlovskiy | 246 | 10 | |
 Serbia | Danilo Petrović | 247 | 11 | |
 Austria | Lucas Miedler | 253 | 12 | |
 Czech Republic | Zdeněk Kolář | 284 | 13 | |
| France | Kenny de Schepper | 288 | 14 | |
| Italy | Luca Vanni | 291 | 15 | |
 India | Sasikumar Mukund | 292 | 16 |
The following players received wildcards into the singles main draw:
The following players received entry into the singles main draw as alternates:
The following players received entry into the singles main draw using their ITF World Tennis Ranking:
Tomás Martín Etcheverry Maxime Hamou Tom Jomby Quentin Robert Matías ZukasThe following players received entry from the qualifying draw:
See main article: 2019 Tilia Slovenia Open – Singles.
Viktor Durasovic 7–5, 6–3.See main article: 2019 Tilia Slovenia Open – Doubles.
Teymuraz Gabashvili / 
Carlos Gómez-Herrera def. Lucas Miedler / Tristan-Samuel Weissborn 6–3, 6–2.
