In Croatia, Koljan families are predominantly Serbs, rarely Croats (from Rijeka ). In the past century, relatively most of Croatian residents bearing this family name were born in Zagreb and in Gospic area.
Prevalence
Only a few people with faimily name Koljan live in Croatia today, in four households only. They are located in two Croatian cities only, in Zagreb (<10) and Rijeka (<5).
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1902 in source Hartmann's General List of Apartments in Zagreb.