| 2025 Istanbul Challenger | |
|---|---|
| Date | 1–7 September |
| Edition | 39th |
| Surface | Hard |
| Location | Istanbul, Turkey |
| Champions | |
| Singles | |
 Alex Molčan | |
| Doubles | |
Miloš Karol /  Daniel Masur | |
The 2025 QNB Istanbul Challenger 77. TED Open was a professional tennis tournament played on hardcourts. It was the 39th edition of the tournament which was part of the 2025 ATP Challenger Tour. It took place in Istanbul, Turkey between 1 and 7 September 2025. [1] [2]
| Country | Player | Rank1 | Seed |
|---|---|---|---|
| SVK | Lukáš Klein | 119 | 1 |
 FIN | Otto Virtanen | 123 | 2 |
 ESP | Martín Landaluce | 138 | 3 |
 FRA | |||
 TUN | Moez Echargui | 165 | 5 |
| FRA | Calvin Hemery | 185 | 6 |
| FRA | Hugo Grenier | 188 | 7 |
 LBN | Benjamin Hassan | 200 | 8 |
 MEX | Rodrigo Pacheco Méndez | 224 | 9 |
The following players received wildcards into the singles main draw:
Kaya Arınç Koray Kırcı Mert Naci Türker The following player received entry into the singles main draw using a protected ranking:
The following players received entry into the singles main draw as alternates:
The following players received entry from the qualifying draw:
Alex Hernández Michal Krajčí
Péter Makk
Ivan Nedelko 
Luca Potenza
Vadym Ursu Alex Molčan def. 
Nicolás Mejía 7–6(11–9), 6–2. Miloš Karol / Daniel Masur def. 
Stefanos Sakellaridis / 
Karan Singh 7–6(7–2), 6–1.