In Croatia, Seidl families are Croats (from Hrvatska Kostajnica ). In the past century, relatively most of Croatian residents bearing this family name were born in Varazdin and Hrvatska Kostajnica.
Prevalence
About 60 people with faimily name Seidl live in Croatia today, in 30 households. There were 40 of them in the middle of the past century, and their number increased by 40 percent. They are located in 10 Croatian counties, in 8 cities and 5 other places, mostly in Zagreb (15), Hrvatska Kostajnica (<10), Koska in Nasice area (<10), Varazdin (<10), and in Pitomaca in Djurdjevac area (<10).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over ten times, the first time 1902 in source Hartmann's General List of Apartments in Zagreb.