Family name Toyomasa (豊昌 
, 豊正 , Toyomasa 
) , globally, is a rare cognomen. The last name Toyomasa is characteristic of Eastern Asia, particularly Taiwan, where it is a rare surname, and China, where it is an extremely rare surname. Also, Toyomasa is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| 豊正, 豊昌 | China |
| Toyomasa | China, Taiwan, Canada |
| toyomasa katagiri researcher |
|