In Croatia, Bayer families are generally Croats (from Pula area ), very rarely Serbs, and . In the past century, relatively most of Croatian residents bearing this family name were born in Zagreb and Varazdin.
Prevalence
About 30 people with faimily name Bayer live in Croatia today, in 18 households. There were 20 of them in the middle of the past century, and their number increased by 20 percent. They are located in 7 Croatian counties, in 8 cities and another small place , mostly in Zagreb (15), Osijek (<5), Varazdin (<5), Sisak (<5), and in Porec (<5).
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.