Green River, WY has a population of 12,574 and is the 3,295th largest city in the United States. The population density is 918 per sq mi which is 15484% higher than the Wyoming average and 913% higher than the national average. The median age in Green River is 37 which is approximately 1% lower than the Wyoming average of 37. In Green River, 58% of the population over 15 years of age are married, 87% speak English and 12% speak Spanish. 39% of Green River residents were born in Wyoming, 54% were born out of state, 1% were born outside of the United States and 6% were foreign born.