Gardner, IL has a population of 1,242 and is the 13,832nd largest city in the United States. The population density is 428 per sq mi which is 92% higher than the Illinois average and 372% higher than the national average. The median age in Gardner is 39 which is approximately 4% higher than the Illinois average of 37. In Gardner, 60% of the population over 15 years of age are married, 98% speak English and 1% speak Spanish. 88% of Gardner residents were born in Illinois, 11% were born out of state, 0% were born outside of the United States and 1% were foreign born.