Tomšić families are Croats and they are mostly from Slunj area. According to some sources they are from Derventa area (Bosnia). In the past century, relatively most of Croatian residents bearing this family name were born in Zagreb and Cakovec. In Poljana Čička in Velika Gorica every ninth inhabitant had the family name Tomšić.
Prevalence
About 680 people with faimily name Tomšić live in Croatia today, in 300 households. There were 560 of them in the middle of the past century, and their number increased by 20 percent. They are located in almost all Croatian counties, in 43 cities and 75 other places, mostly in Zagreb (120), Djakovo (30), Dubrovnik (30), Stitar (25), and in Varazdin (25).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over twenty times, the first time 1902 in source Hartmann's General List of Apartments in Zagreb.