| Date: | 9 – 14 January |
| Edition: | 5th |
| Surface: | Hard |
| Location: | Nonthaburi, Thailand |
| Champs: |  Arthur Cazaux |
| Champd: |  Yuki Bhambri / Saketh Myneni |
| Before Year: | 2023 |
| Before Name: | Nonthaburi Challenger |
| Main Name: | Nonthaburi Challenger |
| After Year: | 2023 |
| After Name: | Nonthaburi Challenger III |
The 2023 Nonthaburi Challenger II was a professional tennis tournament played on hard courts. It was the 5th edition of the tournament which was part of the 2023 ATP Challenger Tour. It took place in Nonthaburi, Thailand from 9 to 14 January 2023.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Austria | Dennis Novak | 180 | 1 | |
| Lloyd Harris | 237 | 2 | ||
 Poland | Kacper Żuk | 245 | 3 | |
 Czech Republic | Zdeněk Kolář | 247 | 4 | |
 Belgium | Michael Geerts | 254 | 5 | |
| Poland | Daniel Michalski | 260 | 6 | |
 Japan | Sho Shimabukuro | 264 | 7 | |
 United States | Tennys Sandgren | 265 | 8 |
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 from the qualifying draw:
Alafia Ayeni Arthur Cazaux
Giovanni FonioSee main article: 2023 Nonthaburi Challenger II – Singles.
Arthur Cazaux def. Lloyd Harris 7–6(7–5), 6–2.See main article: 2023 Nonthaburi Challenger II – Doubles.
Yuki Bhambri / Saketh Myneni def. Christopher Rungkat / 
Akira Santillan 2–6, 7–6(9–7), [14–12].
