Oregon, IL has a population of 3,657 and is the 7,842nd largest city in the United States. The population density is 1,864 per sq mi which is 738% higher than the Illinois average and 1957% higher than the national average. The median age in Oregon is 45 which is approximately 20% higher than the Illinois average of 37. In Oregon, 54% of the population over 15 years of age are married, 92% speak English and 0% speak Spanish. 75% of Oregon residents were born in Illinois, 20% were born out of state, 0% were born outside of the United States and 5% were foreign born.