Cognomen Stiffen (Stiffen 
) , all over the world, is a very rare surname. The cognomen Stiffen is characteristic of Nicaragua, where it is a very rare surname, the United States, and the United Kingdom, where it is an extremely rare surname. Measured by absolute frequency, this name is the most popular in the United States, Nigeria, and the United Kingdom. Likewise, Stiffen is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Stiffen | Indonesia, Mexico, India, United States, Nigeria |