Municipality Osilnica, which is part of the Jugovzhodna Slovenija statistical region, measures 36 km2; this ranks it 159th among Slovene municipalities.
Statistical data for 2023 reveal the following:
In the middle of 2023 about 340 people (about 180 men and 160 women) were living in the municipality, which ranks Osilnica 212th among Slovene municipalities. The population density was 9 people per square kilometre, which was lower than the national average of 105 people per square kilometre.
The number of live births was lower than the number of deaths, which means that natural increase per 1,000 population in the municipality was negative. It was –8.9 (in Slovenia –2.1). The number of people who moved from the municipality was higher than the number of people who moved into the municipality, so net migration per 1,000 population in the municipality was negative. It was –14.8. The sum of natural increase and net migration per 1,000 population in the municipality was negative. It was –23.7 (in Slovenia 3.3).
The mean age of people in Osilnica was 52.9 years, which was higher than the national average (44.1).
As in most Slovene municipalities, in Osilnica the number of old people was higher than the number of young people: there were 481 people, aged 65 or more, per 100 people aged 0–14. This ratio shows that the value of the ageing index was higher than the national average of 145. It also shows that the mean age of people in Osilnica is growing more rapidly than in Slovenia as a whole. Data by sex show that the ageing index for women was in all municipalities except in six (Črna na Koroškem, Dobrovnik/Dobronak, Grad, Hodoš/Hodos, Jezersko in Mislinja) higher than the ageing index for men. In Osilnica – as in most Slovene municipalities – more women were 65+ years old than 14 or less; for men the situation was the same.
Osilnica had no kindergarten. Of all children in the municipality aged 1–5, 71% were included in kindergartens, which was less than the national average of 83%. Osilnica also had no elementary school. In the school year 2023/24 various upper secondary schools were attended by about 10 pupils. There were 15 students and no graduates per 1,000 people in the municipality; in Slovenia the averages were 38 per 1,000 and 8 per 1,000, respectively.
Among people aged 15–64 (i.e. working age population) about 55% were persons in employment (i.e. persons in paid employment or self–employed persons), which is less than the national average (69%).
Among 1,000 inhabitants in the municipality, 568 had a passenger car. The car was on average 11 years old.
In 2023, 128 kg of municipal waste per person was collected in Osilnica, which is 250 kg less than on average in Slovenia.