Surname Postum (Posthumus 
, Postum 
) , all around the world, is quite a rare last name. The last name Postum is characteristic of Netherlands, where it is quite a common surname, South Africa, where it is quite a rare surname, and Canada, where it is a rare surname. In absolute terms, this name is the most popular in Netherlands, South Africa, and the United States.
| VARIANT | COUNTRY |
|---|---|
| Posthumus | Netherlands, Canada, United States, Germany, South Africa |
| Postum | India, United States, South Africa |