In Croatia, Polonio families are Italians (from the Island of Losinj ). In the past century, relatively most of Croatian residents bearing this family name were born on the Island of Losinj.
Prevalence
Only a few people with faimily name Polonio live in Croatia today, in two households only. There were 10 of them in the middle of the past century, and their number decreased significantly. They are located in two Croatian cities only, in Osor on the Island of Losinj (<5) and Krk on the Island of Krk (<5).
Outside Croatia
Family name Polonio is present in 29 countries worldwide.
In the sources analysed in the project Acta Croatica so far, the name is mentioned over five times, the first time 1906 in source Yearbook and Directory of Literary Society of St. Jerome 1906.