Natsumi Kawaguchi
| Country (sports) | Japan |
|---|---|
| Born | 28 June 2002 Nagasaki Prefecture, Japan |
| Height | 1.63 m (5 ft 4 in) |
| Plays | Left (two-handed backhand) |
| Prize money | $67,809 |
| Singles | |
| Career record | 127–82 |
| Career titles | 4 ITF |
| Highest ranking | No. 346 (9 October 2023) |
| Current ranking | No. 578 (27 October 2025) |
| Doubles | |
| Career record | 88–62 |
| Career titles | 4 ITF |
| Highest ranking | No. 232 (4 December 2023) |
| Current ranking | No. 326 (27 October 2025) |
| Last updated on: 27 October 2025. | |
Natsumi Kawaguchi (川口夏実, Kawaguchi Natsumi; born 28 June 2002) is a Japanese tennis player.
On 9 October 2023, she has achieved career-high rankings of 346 in singles and on 4 December 2023 of 232 in doubles.
Kawaguchi and her partner Adrienn Nagy won the 2019 Australian girls' doubles title, beating Emma Navarro and Chloe Beck in the final.
She qualified for the main draw of the WTA 500 2023 Pan Pacific Open at home in Tokyo but had to withdraw shortly after.