| 2025 Nonthaburi Challenger III | |
|---|---|
| Date | 13 – 19 January |
| Edition | 13th |
| Surface | Hard |
| Location | Nonthaburi, Thailand |
| Champions | |
| Singles | |
 Brandon Holt | |
| Doubles | |
 Ray Ho /  Neil Oberleitner | |
The 2025 Nonthaburi Challenger III was a professional tennis tournament played on hard courts. It was the 13th edition of the tournament which was part of the 2025 ATP Challenger Tour. It took place in Nonthaburi, Thailand from 13 to 19 January 2025. [1]
| Country | Player | Rank1 | Seed |
|---|---|---|---|
 CZE | Vít Kopřiva | 125 | 1 |
 FRA | Hugo Grenier | 154 | 2 |
 MON | Valentin Vacherot | 162 | 3 |
| USA | Zachary Svajda | 165 | 4 |
 JPN | Shintaro Mochizuki | 170 | 5 |
 HKG | Coleman Wong | 172 | 6 |
 GER | Henri Squire | 178 | 7 |
 KAZ | Dmitry Popko | 183 | 8 |
The following players received wildcards into the singles main draw:
Thanapet Chanta Maximus Jones Wishaya Trongcharoenchaikul The following players received entry into the singles main draw as alternates:
The following players received entry from the qualifying draw:
Brandon Holt def. Vít Kopřiva 6–3, 6–2. Ray Ho / Neil Oberleitner def. Pruchya Isaro / 
Wang Aoran 6–3, 6–4.
