Mountain Green, UT has a population of 3,113 and is the 8,619th largest city in the United States. The population density is 576 per sq mi which is 1611% higher than the Utah average and 535% higher than the national average. The median age in Mountain Green is 29 which is approximately 3% lower than the Utah average of 30. In Mountain Green, 81% of the population over 15 years of age are married, 96% speak English and 1% speak Spanish. 68% of Mountain Green residents were born in Utah, 28% were born out of state, 0% were born outside of the United States and 4% were foreign born.