Olney, MT has a population of 200 and is the 24,441st largest city in the United States. The population density is 150 per sq mi which is 2102% higher than the Montana average and 66% higher than the national average. The median age in Olney is 39 which is approximately 2% lower than the Montana average of 40. In Olney, 61% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 45% of Olney residents were born in Montana, 56% were born out of state, 0% were born outside of the United States and 0% were foreign born.