Kenchō (建長) was a Japanese era name (年号, nengō,, lit. "year name") after Hōji and before Kōgen. This period spanned the years from March 1249 to October 1256. The reigning emperor was Go-Fukakusa-tennō (後深草天皇).
Change of era
- 1249 Kenchō gannen (建長元年): The new era name was created to mark an event or a number of events. The previous era ended and a new one commenced in Hōji 3.