Kljak families are Croats and they are mostly from Ivanic-Grad area. In the past century, relatively most of Croatian residents bearing this family name were born in Zagreb and Zlatar.
Prevalence
About 90 people with faimily name Kljak live in Croatia today, in 30 households. There were 100 of them in the middle of the past century, and their number decreased by 10 percent. They are only located in four Croatian cities and 7 other places, mostly in Repno (25), Zagreb (15), Ivanic-Grad (15), Cemernica Lonjska in Ivanic-Grad area (10), and in Borkovec (<10).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over twenty times, the first time 1906 in source Yearbook and Directory of Literary Society of St. Jerome 1906.