In Croatia, Ondej families are Croats (from Krapina area ). In the past century, relatively most of Croatian residents bearing this family name were born in Bosanian Posavina (Brcko area) and in Zagreb.
Prevalence
About 10 people with faimily name Ondej live in Croatia today, in 6 households. There were 0 of them in the middle of the past century, and their number multiplied. They are located in only four naselja i to in Zagreb (<5), Krapinske Toplice in Krapina area (<5), Gunja in Zupanja area (<5), and in Goli Breg (<5).