Kagen (嘉元) was a Japanese era (年号,, nengō,; lit. "year name") after Kengen and before Tokuji. This period started in August 1303 and ended in December 1306. During this time, the emperor was Go-Nijō-tennō (後二条天皇).
| Kagen | 1st | 2nd | 3rd | 4th |
|---|---|---|---|---|
| 1303 | 1304 | 1305 | 1306 |
| Preceded by: Kengen |
Era or nengō: Kagen |
Succeeded by: Tokuji |