In Croatia, Gjeldum families are Croats (from Trogir ). In the past century, relatively most of Croatian residents bearing this family name were born in Trogir and Split.
Prevalence
About 40 people with faimily name Gjeldum live in Croatia today, in 20 households. There were 50 of them in the middle of the past century, and their number decreased by 20 percent. They are located in threee Croatian counties and 5 other places, mostly in Split (10), Trogir (<10), Marinici in Rijeka area (<10), Zagreb (<5), and in Drvenik in Ploce area (<5).
Outside Croatia
Family name Gjeldum is present in three countries on three continents. The family name "Gjeldum " is used by some 70 people in the United States and small number in Argentina.
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.