Šešelja families are Croats and they are mostly from Dugi (Long) Island. In the past century, relatively most of Croatian residents bearing this family name were born in Zadar and on Dugi, Long Island. In Zaglav on Dugi (Long) Island every fifth inhabitant had the family name Šešelja.
Prevalence
About 80 people with faimily name Šešelja live in Croatia today, in 40 households. There were 80 of them in the middle of the past century, and their number remains constant. They are located in four Croatian counties and four other places, mostly in Zaglav on Dugi (Long) Island (45), Zadar (25), Zagreb (<5), Rijeka (<5), and in Pula (<5).
Outside Croatia
Family name Šešelja (including: Seselja , Seselia ) is present in 9 countries worldwide.
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 2007 in source Encyclopaedia of Croatian Surnames.