Last name גאידר (Qaydar 
, Gaidar 
, Gaydar 
) , across the world, is a rare family name. The surname גאידר is characteristic of Estonia, where it is a rare surname, Georgia, and Israel. In absolute terms, it is commonest in the United States, India, and Russia. Also, גאידר is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Qaydar | Iraq, United States |
| Gaidar | Russia, Poland, United States, India, Argentina |
| Gaydar | Russia, United States, Argentina, Canada, Ukraine |
| גאידר | Israel |