| H4H | |
|---|---|
| |
| Role | Patrol flying boat |
| National origin | Japan |
| Manufacturer | Hiro Naval Arsenal |
| First flight | 1931 |
| Introduction | 1933 |
| Primary user | IJN Air Service |
| Number built | 47 |
The Hiro H4H (or Hiro Navy Type 91 Flying Boat) was a 1930s Japanese bomber or reconnaissance monoplane flying boat designed and built by the Hiro Naval Arsenal for the Imperial Japanese Navy.