Globally, Kustak (Kustak 
) is a very rare mostly boy's, but uncommonly girly forename. The given name Kustak is habitual in Southern Asia, particularly India, where it is an extremely rare mostly male, but uncommonly girly name. Likewise, Kustak is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Kustak | Poland, India, Germany, Turkey, United States |