Kopilaš families are Croats and they are mostly from north Herzegovina. According to some sources they are from Siroki Brijeg (Bosnia). In the past century, relatively most of Croatian residents bearing this family name were born in North Herzegovina (Konjic area) and in North Herzegovina (Jablanica area). In Donji Gradac in North Herzegovina every fifth inhabitant had the family name Kopilaš.
Prevalence
About 70 people with faimily name Kopilaš live in Croatia today, in 30 households. There were 20 of them in the middle of the past century, and their number more than tripled. They are located in 10 Croatian counties, in 13 cities and four other places, mostly in Zagreb (15), Vinkovci (10), Ilok (10), Pozega (<10), and in Mravince (<10).
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 2007 in source Encyclopaedia of Croatian Surnames.