Old Green, OK has a population of 622 and is the 18,209th largest city in the United States. The population density is 193 per sq mi which is 254% higher than the Oklahoma average and 113% higher than the national average. The median age in Old Green is 22 which is approximately 40% lower than the Oklahoma average of 36. In Old Green, 52% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 59% of Old Green residents were born in Oklahoma, 41% were born out of state, 0% were born outside of the United States and 0% were foreign born.