In Croatia, Trapp families are Croats (from the Island of Rab ). In the past century, relatively most of Croatian residents bearing this family name were born in Rijeka.
Prevalence
Only a few people with faimily name Trapp live in Croatia today, in three households only. There were 0 of them in the middle of the past century, and their number remains constant. They are located in only one small Croatian place, in Palit on the Island of Rab (<10).
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1929 in source Emigration Commission Zagreb.