Sedlaček families are often Croats and they are mostly from Semberija (Bosnia), less frequently Czechs (from Grubisno Polje ). In the past century, relatively most of Croatian residents bearing this family name were born in Grubisno Polje and Virovitica. In Batar in Semberia (Bosnia) every eighth inhabitant had the family name Sedlaček.
Prevalence
About 130 people with faimily name Sedlaček live in Croatia today, in 60 households. There were 150 of them in the middle of the past century, and their number decreased by 20 percent. They are located in 10 Croatian counties, in 15 cities and 20 other places, mostly in Treglava (15), Zagreb (15), Garesnica (10), Resetari in Nova Gradiska area (10), and in Pozega (<10).
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1917 in source List of Dignitaries, Officials and Public Servants of the Kingdom of Croatia-Slavonia.