Hillsdale, OK has a population of 150 and is the 25,663rd largest city in the United States. The population density is 415 per sq mi which is 661% higher than the Oklahoma average and 358% higher than the national average. The median age in Hillsdale is 38 which is approximately 4% higher than the Oklahoma average of 36. In Hillsdale, 72% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 79% of Hillsdale residents were born in Oklahoma, 21% were born out of state, 0% were born outside of the United States and 0% were foreign born.