In 2022, the population of Foss was 99, a 1.98% decrease year-by-year from 2021. Previously, in 2021, Foss's population was 101, a decline of 0.00% compared to a population of 101 in 2020.
The median age in Foss, OK is 56.6, as per 2021 ACS 5-Year Estimates. Of the total population, 9.09% were under the age of 15, 10.74% aged 15 to 29, 41.32% aged 30 to 64, 36.36% aged 65 to 84, and 2.48% were 85 years of age and older.