Around the world, Ostacia (Ostacia 
) is a rare feminine forename. The given name Ostacia is characteristic of the Democratic Republic of the Congo, where it is a rare female name, and Brazil, where it is an extremely rare feminine name. Much less frequently, Ostacia is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Ostacia | Nicaragua, Brazil, Mexico, Democratic Republic of the Congo, Venezuela |