Humboldt, IL has a population of 483 and is the 19,735th largest city in the United States. The population density is 1,386 per sq mi which is 524% higher than the Illinois average and 1430% higher than the national average. The median age in Humboldt is 46 which is approximately 24% higher than the Illinois average of 37. In Humboldt, 65% of the population over 15 years of age are married, 92% speak English and 8% speak Spanish. 87% of Humboldt residents were born in Illinois, 8% were born out of state, 0% were born outside of the United States and 5% were foreign born.