Robinson, IL has a population of 7,447 and is the 4,958th largest city in the United States. The population density is 1,572 per sq mi which is 607% higher than the Illinois average and 1635% higher than the national average. The median age in Robinson is 39 which is approximately 4% higher than the Illinois average of 37. In Robinson, 51% of the population over 15 years of age are married, 93% speak English and 4% speak Spanish. 71% of Robinson residents were born in Illinois, 25% were born out of state, 1% were born outside of the United States and 4% were foreign born.