| Keio Challenger | |
| Type: | joint |
| Current: | 2024 Keio Challenger |
| Event Name: | Keio Challenger |
| Location: | Yokohama, Japan |
| Venue: | Mamushidani Tennis Courts, Keio University |
| Surface: | Hard |
| Website: | Website |
| Atp Category: | ATP Challenger Tour |
| Atp Draw: | 32S/32Q/16D |
| Atp Prize Money: | $50,000+H |
| Wta Tier: | ITF Women's Circuit |
| Wta Draw: | 32S/32Q/16D |
| Wta Prize Money: | $40,000 |
The Keio Challenger is a professional tennis tournament played on hardcourts.[1] It is currently part of the ATP Challenger Tour and the ITF Women's Circuit.[2] Having been held in Yokohama, Japan since 1999, the women's edition of the event was introduced in 2017.[3] [4]
| Year | Champion | Runner-up | Score | |
|---|---|---|---|---|
 Yuta Shimizu | 6–7(4–7), 6–4, 6–2 | |||
| Yosuke Watanuki | 7–6(7–5), 6–4 | |||
 Christopher O'Connell | 6–1, 6–7(5–7), 6–3 | |||
| 2020–21 | Not held | |||
 Kwon Soon-woo | 7–6(7–4), 6–3 | |||
| Yasutaka Uchiyama | 2–6, 6–3, 6–4 | |||
| Yūichi Sugita | 6–4, 2–6, 7–6(7–2) | |||
| 2016 | Not held | |||
| Taro Daniel | 4–6, 6–3, 6–3 | |||
| John Millman | 6–4, 6–4 | |||
| Matthew Ebden | 2–6, 7–6(7–3), 6–3 | |||
 Matteo Viola | 7–6(7–3), 6–3 | |||
| 2010–11 | Not held | |||
| Takao Suzuki | 6–4, 7–6(7−5) | |||
| 2008 | Lee Hyung-taik | 7–5, 6–3 | ||
| 2007 |  Dudi Sela | 6–7(5−7), 6–4, 6–2 | ||
| 2003–06 | Not held | |||
| 2002 | Lee Hyung-taik | 2–6, 7–6(7−2), 7–6(8−6) | ||
| 2001 | Takao Suzuki | 6–2, 6–7(5−7), 7–6(7−4) | ||
| 2000 | Eric Taino | 7–6(7−5), 6–4 | ||
| 1999 | Lee Hyung-taik | 6–3, 6–0 |
| Year | Champions | Runners-up | Score | |
|---|---|---|---|---|
Benjamin Hassan Saketh Myneni | 6–2, 6–4 | |||
 Filip BergeviMick Veldheer | 2–6, 7–5, [11–9] | |||
 Victor Vlad CorneaRuben Gonzales | 7–5, 6–3 | |||
| 2020–21 | Not held | |||
 Moez Echargui Skander Mansouri | 7–6(8–6), 6–7(3–7), [10–7] | |||
| Tobias Kamke Tim Pütz | 3–6, 7–5, [12–10] | |||
| Marin Draganja Tomislav Draganja | 4–6, 6–3, [10–4] | |||
| 2016 | Not held | |||
 Sanchai Ratiwatana Sonchat Ratiwatana | 6–4, 6–4 | |||
 Bradley Klahn Matt Reid | 4–6, 6–4, [10–7] | |||
Bradley Klahn Michael Venus | 7–5, 6–1 | |||
Prakash Amritraj Philipp Oswald | 6–3, 6–4 | |||
| 2010–11 | Not Held | |||
| Yang Tsung-hua Yi Chu-huan | 6–7(9−11), 6–3, [12–10] | |||
| 2008 |  Tomáš Cakl Marek Semjan | 6–3, 7–6(7−1) | ||
| 2007 | Hiroki Kondo Go Soeda | 6–7(5−7), 6–3, [11–9] | ||
| 2003–06 | Not held | |||
| 2002 | Lu Yen-hsun Danai Udomchoke | 7–6(7−5), 6–3 | ||
| 2001 | Takao Suzuki Mitsuru Takada | 6–3, 6–4 | ||
| 2000 | Yves Allegro Julian Knowle | 6–3, 7–6(7−2) | ||
| 1999 | Satoshi Iwabuchi Thomas Shimada | 6–2, 6–4 |
| Year | Champion | Runner-up | Score | |
|---|---|---|---|---|
| Aliona Falei | 3–6, 6–1, 6–4 | |||
| Aliona Falei | 6–3, 7–5 | |||
| Han Na-lae | 7–5, 6–0 | |||
| 2021 | Not held | |||
| 2020 | Yuriko Miyazaki | 7–5, 5–7, 6–2 | ||
 Greet Minnen | 6–4, 6–1 | |||
 Veronika Kudermetova | 6–2, 6–4 | |||
| Akiko Omae | 7–5, 6–2 |
| Year | Champions | Runners-up | Score | |
|---|---|---|---|---|
| Momoko Kobori Ayano Shimizu | 6–4, 7–6(7–2) | |||
Liang En-shuo Tang Qianhui | Walkover | |||
| Saki Imamura Naho Sato | 6–4, 4–6, [10–5] | |||
| 2021 | Not held | |||
| 2020 | Robu Kajitani Naho Sato | 1–6, 6–4, [10–8] | ||
| Choi Ji-hee Han Na-lae | 6–1, 7–5 | |||
 Laura Robson Fanny Stollár | 5–7, 6–2, [10–4] | |||
| Ayaka Okuno Erika Sema | 6–4, 6–4 |