| 2025 Keio Challenger | ||||
|---|---|---|---|---|
| Date | 17 – 23 November (men's) 24 – 30 November (women's) | |||
| Edition | 18th (men's) 8th (women's) | |||
| Category | ATP Challenger Tour ITF Women's World Tennis Tour | |||
| Surface | Hard | |||
| Location | Yokohama, Japan | |||
| 2024 Champions | ||||
| Women's singles | ||||
 Aliona Falei | ||||
| Women's doubles | ||||
 Momoko Kobori /Ayano Shimizu | ||||
| Champions | ||||
| Men's singles | ||||
| Rei Sakamoto | ||||
| Men's doubles | ||||
 Neil Oberleitner / Michael Vrbenský | ||||
| ||||
The2025Yokohama Keio Challenger was a professionaltennis tournament played onhardcourts. It was the 18th (men's) and 8th (women's) editions of the tournament and part of the2025 ATP Challenger Tour and the2025 ITF Women's World Tennis Tour. It took place inYokohama, Japan between 17 and 30 November 2025.
| Country | Player | Rank1 | Seed |
|---|---|---|---|
| JPN | Kei Nishikori | 159 | 1 |
| JPN | Rei Sakamoto | 180 | 2 |
 SWE | Elias Ymer | 191 | 3 |
 GBR | Oliver Crawford | 193 | 4 |
 TPE | Hsu Yu-hsiou | 220 | 5 |
| JPN | Yuta Shimizu | 249 | 6 |
| JPN | Yasutaka Uchiyama | 305 | 7 |
| JPN | Kaichi Uchida | 309 | 8 |
The following players received wildcards into the singles main draw:
Masamichi Imamura Lennon Roark Jones Ryo TabataThe following player received entry into the singles main draw through the Junior Accelerator programme:
The following players received entry from the qualifying draw:
Taisei Ichikawa Yusuke Kusuhara
Igor Marcondes Ryotaro TaguchiMichael Vrbenský Jumpei Yamasaki| Country | Player | Rank1 | Seed |
|---|---|---|---|
 CHN | Zhang Shuai | 102 | 1 |
| JPN | Himeno Sakatsume | 181 | 2 |
 THA | Mananchaya Sawangkaew | 222 | 3 |
| CHN | Ma Yexin | 227 | 4 |
 USA | Hina Inoue | 232 | 5 |
 KOR | Ku Yeon-woo | 255 | 6 |
| USA | Hanna Chang | 273 | 7 |
| JPN | Haruka Kaji | 277 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry from the qualifying draw:
Rei Sakamoto def.Kaichi Uchida 4–6, 7–6(7–4), 6–4. vs.Neil Oberleitner /Michael Vrbenský def.Masamichi Imamura / Ryuki Matsuda 7–6(8–6), 6–1. / vs. /