Williams, IA has a population of 468 and is the 19,941st largest city in the United States. The population density is 538 per sq mi which is 884% higher than the Iowa average and 493% higher than the national average. The median age in Williams is 35 which is approximately 9% lower than the Iowa average of 38. In Williams, 66% of the population over 15 years of age are married, 97% speak English and 1% speak Spanish. 87% of Williams residents were born in Iowa, 10% were born out of state, 0% were born outside of the United States and 3% were foreign born.