Šimić families are almost entirely Croats and they are mostly from Herzegovina. According to some sources they are from Italy, and barely Serbs. In the past century, relatively most of Croatian residents bearing this family name were born in Herzegovina (Grude area) and in Zagreb. In Rapače in Tuzla Region (Bosnia) every second inhabitant had the family name Šimić.
About 6200 people with faimily name Šimić live in Croatia today, in 2500 households. There were 3000 of them in the middle of the past century, and their number doubled. They are located in all Croatian counties, in 112 cities and 476 other places, mostly in Zagreb (1145), Split (350), Osijek (265), Sesvete (230), and in Djakovo (165).