# 2025 ITF Nonthaburi – Singles

Antonia Ružić was the defending champion but chose not to participate.
Kyōka Okamura won the title, defeating Kathinka von Deichmann in the final; 7–5, 1–6, 7–5.

## Seeds

* Kathinka von Deichmann (final)
* Lanlana Tararudee (quarterfinals, withdrew)
* Shi Han (second round)
* Carole Monnet (second round)
* Hanne Vandewinkel (quarterfinals)
* Kyōka Okamura (champion)
* Ma Yexin (quarterfinals)
* Maria Mateas (quarterfinals)

## Draw
### Key

* Q = Qualifier
* WC = Wild card
* LL = Lucky loser
* Alt = Alternate
* SE = Special exempt
* PR = Protected ranking
* ITF = ITF entry
* JE = Junior exempt
* w/o = Walkover
* r = Retired
* d = Defaulted
* SR = Special ranking

### Finals

| Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final | Final |
| 1 | Kathinka von Deichmann | 6 | 6 | | | | | |
| | Sahaja Yamalapalli | 0 | 3 | | | | | |
| | Sahaja Yamalapalli | 0 | 3 | 1 | Kathinka von Deichmann | 5 | 6 | 5 |
| | | | | 6 | Kyōka Okamura | 7 | 1 | 7 |
| | Claire Liu | | | 6 | Kyōka Okamura | 7 | 1 | 7 |
| 6 | Kyōka Okamura | w/o | | | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | K von Deichmann | 6 | 6 | | | | | | | | | | | | | | | |
| | M Tkacheva | 2 | 3 | | 1 | K von Deichmann | 6 | 6 | | | | | | | | | | |
| Q | C Wong | 6 | 7$^9$ | | Q | C Wong | 2 | 2 | | | | | | | | | | |
| Q | G Crăciun | 4 | 6$^7$ | | | | | | | 1 | K von Deichmann | 6 | 7 | | | | | |
| Q | V Chaudhari | 6 | 4 | 2 | | | | | | 5 | H Vandewinkel | 1 | 5 | | | | | |
| | J Lu | 3 | 6 | 6 | | J Lu | 2 | 2 | | | | | | | | | | |
| Q | E Chong | 6 | 1 | 5 | 5 | H Vandewinkel | 6 | 6 | | | | | | | | | | |
| 5 | H Vandewinkel | 4 | 6 | 7 | | | | | | | | | | | 1 | K von Deichmann | 6 | 6 |
| 3 | H Shi | 6 | 6 | | | | | | | | | | | | | S Yamalapalli | 0 | 3 |
| | A Rogers | 4 | 0 | | 3 | H Shi | 7 | 0 | 2 | | | | | | | | | |
| WC | K Yodpetch | 3 | 4 | | | S Yamalapalli | 5 | 6 | 6 | | | | | | | | | |
| | S Yamalapalli | 6 | 6 | | | | | | | | S Yamalapalli | 6 | 5 | 6 | | | | |
| SR | D Astakhova | 6 | 4 | 6$^5$ | | | | | | 8 | M Mateas | 3 | 7 | 3 | | | | |
| Q | R Saigo | 2 | 6 | 7$^7$ | Q | R Saigo | 6$^2$ | 6$^3$ | | | | | | | | | | |
| Q | A Kulikova | 6$^4$ | 1 | | 8 | M Mateas | 7$^7$ | 7$^7$ | | | | | | | | | | |
| 8 | M Mateas | 7$^7$ | 6 | | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals |
| 7 | Y Ma | 6 | 4 | 6 | | | | | | | | | | | | |
| WC | P Cheapchandej | 2 | 6 | 4 | 7 | Y Ma | 3 | 6 | 6 | | | | | | | |
| | X Yao | 7 | 7 | | | X Yao | 6 | 3 | 3 | | | | | | | |
| | M Yamaguchi | 5 | 5 | | | | | | | 7 | Y Ma | 5 | 6$^4$ | | | |
| | C Liu | 6 | 6 | | | | | | | | C Liu | 7 | 7$^7$ | | | |
| WC | T Naklo | 3 | 0 | | | C Liu | 0 | 7$^8$ | 6 | | | | | | | |
| | X You | 7$^7$ | 0 | 3 | 4 | C Monnet | 6 | 6$^6$ | 4 | | | | | | | |
| 4 | C Monnet | 6$^4$ | 6 | 6 | | | | | | | | | | | C Liu | |
| 6 | K Okamura | 6 | 0 | 6 | | | | | | | | | | 6 | K Okamura | w/o |
| Q | W Zheng | 3 | 6 | 3 | 6 | K Okamura | 6 | 6 | | | | | | | | |
| WC | P Kovapitukted | 5 | 0 | | | T Andrianjafitrimo | 1 | 3 | | | | | | | | |
| | T Andrianjafitrimo | 7 | 6 | | | | | | | 6 | K Okamura | w/o | | | | |
| | S-j Jang | 6 | 7 | | | | | | | 2 | L Tararudee | | | | | |
| Q | M Kuramochi | 2 | 5 | | | S-j Jang | 5 | 6$^4$ | | | | | | | | |
| SR | K Dmitruk | 3 | 2 | | 2 | L Tararudee | 7 | 7$^7$ | | | | | | | | |
| 2 | L Tararudee | 6 | 6 | | | | | | | | | | | | | |