Hammerin' Harry, known in Japan as Daiku no Gen-san (大工の源さん, Carpenter Gen), is a series of platforming video games developed and published by Irem in 1990.

The series is centered around the titular Harry (or "Genzo Tamura" in the original Japanese), a hammer-wielding carpenter who protects his hometown of Beranme from the corrupt construction companies that mean to tear it down.

[1] Julian Rignall of Computer and Video Games magazine gave it a 91% score.

Outside of the franchise, Hammerin' Harry was represented in a Japan-only Game Boy title, Shuyaku Sentai Irem Fighter along with three other Irem franchises: R-Type, Ninja Spirit and Mr. Heli.

Hammerin' Harry can be seen on the arcade flyers of Ninja Baseball Bat Man, also by Irem.