Cognomen ضيائ (ضيائ 
) , all around the world, is an extremely rare last name. The family name ضيائ is habitual in Southern Asia, particularly Iran, where it is a very rare surname. Much more frequently, ضيائ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| ضيائ | Iraq, Iran |