In 2022, the population of Osyka was 369, a 1.07% decrease year-by-year from 2021. Previously, in 2021, Osyka's population was 373, a decline of 0.53% compared to a population of 375 in 2020.
The median age in Osyka, MS is 43.5, as per 2021 ACS 5-Year Estimates. Of the total population, 14.33% were under the age of 15, 24.52% aged 15 to 29, 44.08% aged 30 to 64, 14.33% aged 65 to 84, and 2.75% were 85 years of age and older.