Oljača families are mainly Serbs and they are mostly from Bosnian Posavina , whereas often Croats (from Vukovar ). In the past century, relatively most of Croatian residents bearing this family name were born in Bosanian Posavina (Bosanski Novi area) and in Vukovar. In places Vedovica and Mala Novska Rujiška in Bosanian Posavina every ninth inhabitant had the family name Oljača.
Prevalence
About 140 people with faimily name Oljača live in Croatia today, in 70 households. There were 120 of them in the middle of the past century, and their number increased by 20 percent. They are located in the most of Croatian counties, in 20 cities and 17 other places, mostly in Trpinja in Vukovar area (20), Zagreb (20), Borovo in Vukovar area (20), Vukovar (15), and in Velika Gorica (<10).
Outside Croatia
At least seven families with this surname emigrated from Croatia to: Germany (3), the United States (2), Norway (1), and to Australia (1). Family name Oljača is present in 12 countries on three continents. The family name "Oljaca " is used by some 60 people in Germany , about 50 in the United States , and small number of people in Greece.
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1924 in source Emigration Commission Zagreb.
