Family name Diosan (Diosan 
) , worldwide, is a rare cognomen. The cognomen Diosan is characteristic of Aland Islands, where it is quite a common surname, Romania, where it is quite a rare surname, and Philippines, where it is a rare surname. Measured by absolute frequency, it is the most numerous in Romania, Philippines, and Saudi Arabia. Much less frequently, Diosan is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Diosan | Spain, Philippines, Saudi Arabia, Aland Islands, Romania |