Cognomen Sustikas (Sustikas 
) , around the globe, is a very rare family name. The last name Sustikas is habitual in Northern Europe, particularly Lithuania, where it is a rare surname, Latvia, and Estonia. Measured by absolute frequency, it most frequently occurs in Lithuania, Latvia, and Brazil.
| VARIANT | COUNTRY |
|---|---|
| Sustikas | Brazil, United Kingdom, Latvia, Lithuania, Estonia |