Harada Sanosuke
| Harada Sanosuke | |
|---|---|
| Native name | 原田 左之助 | 
| Born | 1840 Iyo-Matsuyama Domain, Japan | 
| Died | July 6, 1868 (aged 27–28) Ueno, Edo, Japan | 
| Allegiance | Tokugawa bakufu | 
| Service | Rōshigumi (former) Mibu Rōshigumi (former) Shinsengumi (former) Seiheitai (former) Shōgitai | 
| Years of service | 1863–1868 | 
| Battles / wars | Ikedaya incident Kinmon Incident Sanjo Seisatsu incident Aburanokōji incident Boshin War | 
| Spouse(s) | Harada Masa (m. 1865–1868) | 
| Children | Harada Shigeru (son) | 
Harada Sanosuke (原田 左之助, 1840 – July 6, 1868) was a Japanese warrior (samurai) who lived in the late Edo period. He was the 10th unit captain of the Shinsengumi, and died during the Boshin War.