Griggsville, IL has a population of 1,325 and is the 13,447th largest city in the United States. The population density is 1,231 per sq mi which is 454% higher than the Illinois average and 1258% higher than the national average. The median age in Griggsville is 36 which is approximately 4% lower than the Illinois average of 37. In Griggsville, 72% of the population over 15 years of age are married, 97% speak English and 3% speak Spanish. 82% of Griggsville residents were born in Illinois, 17% were born out of state, 0% were born outside of the United States and 1% were foreign born.