In Croatia, Oleš families are Croats by relative majority (from Pleternica area ), equally Serbs. In the past century, relatively most of Croatian residents bearing this family name were born in Pleternica area.
Prevalence
Only a few people with faimily name Oleš live in Croatia today, in one household only. There were 10 of them in the middle of the past century, and their number decreased significantly. They are located in one Croatian city only, in Pleternica (<5).