In Croatia, Ostić families are predominantly Croats (from Hrvatska Kostajnica ), rarely Serbs. In the past century, relatively most of Croatian residents bearing this family name were born in Pozega area and in Rijeka.
Prevalence
About 50 people with faimily name Ostić live in Croatia today, in 20 households. There were 30 of them in the middle of the past century, and their number increased by 80 percent. They are located in 7 Croatian counties, in 8 cities and four other places, mostly in Zagreb (<10), Lovran in Opatija area (<10), Utolica (<10), Rijeka (<5), and in Velika Gorica (<5).
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.