In Croatia, Koviljčić families are mainly Croats (from Bosnian Posavina ), less frequently Serbs. In the past century, relatively most of Croatian residents bearing this family name were born in Zagreb and in Pleternica area.
Prevalence
Only a few people with faimily name Koviljčić live in Croatia today, in two households only. There were 10 of them in the middle of the past century, and their number remains constant. They are located in only threee Croatian places: in Zagreb (<5), Migalovci in Pleternica area (<5), and in Busevec (<5).
Outside Croatia
Family name Koviljčić is present in two countries on two continents.