In Croatia, Sepčić families are almost entirely Croats (from the Island of Cres ), very rarely Slovenes (from Rijeka ). In the past century, relatively most of Croatian residents bearing this family name were born in Zagreb and Rijeka.
Prevalence
About 30 people with faimily name Sepčić live in Croatia today, in 11 households. There were 60 of them in the middle of the past century, and their number halved. They are located in four Croatian cities only: in Cres on the Island of Cres (15), Zagreb (10), Rijeka (<5), and in Donja Stubica (<5).
Outside Croatia
At least one family with this surname emigrated from Croatia to the United States. Family name Sepčić (including: Sepcic , Sepcich ) is present in three countries on two continents. The family name "Sepcic " is used by some 100 people in the United States. "Sepcich " is used by small number of people in the United States.
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.