In Croatia, Kastelic families are predominantly Croats (from Opatija area ), rarely Italians (from Rijeka ), and very rarely Slovenes (from Novigrad ). In the past century, relatively most of Croatian residents bearing this family name were born in Rijeka and Nova Gradiska.
Prevalence
About 20 people with faimily name Kastelic live in Croatia today, in 12 households. There were 10 of them in the middle of the past century, and their number doubled. They are located in four Croatian counties, in 6 cities and two other places, mostly in Rijeka (<10), Varazdin (<10), Zagreb (<5), Opatija (<5), and in Matulji in Opatija area (<5).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over ten times, the first time 1923 in source Emigration Commission Zagreb.