In Croatia, Sivaček families are Czechs by relative majority (from Banat, Vojvodina ), equally Croats. In the past century, relatively most of Croatian residents bearing this family name were born in Banat, Vojvodina.
Prevalence
Only a few people with faimily name Sivaček live in Croatia today, in two households only. They are located in one Croatian city only, in Pula (<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.