Austin, IN has a population of 3,938 and is the 7,510th largest city in the United States. The population density is 1,505 per sq mi which is 738% higher than the Indiana average and 1561% higher than the national average. The median age in Austin is 39 which is approximately 5% higher than the Indiana average of 37. In Austin, 60% of the population over 15 years of age are married, 97% speak English and 3% speak Spanish. 70% of Austin residents were born in Indiana, 30% were born out of state, 0% were born outside of the United States and 1% were foreign born.