Twin Grove, IL has a population of 1,929 and is the 11,225th largest city in the United States. The population density is 486 per sq mi which is 119% higher than the Illinois average and 436% higher than the national average. The median age in Twin Grove is 47 which is approximately 25% higher than the Illinois average of 37. In Twin Grove, 73% of the population over 15 years of age are married, 98% speak English and 0% speak Spanish. 78% of Twin Grove residents were born in Illinois, 21% were born out of state, 0% were born outside of the United States and 1% were foreign born.