Willow Valley, AZ has a population of 844 and is the 16,235th largest city in the United States. The population density is 171 per sq mi which is 197% higher than the Arizona average and 89% higher than the national average. The median age in Willow Valley is 63 which is approximately 71% higher than the Arizona average of 37. In Willow Valley, 60% of the population over 15 years of age are married, 97% speak English and 0% speak Spanish. 5% of Willow Valley residents were born in Arizona, 86% were born out of state, 6% were born outside of the United States and 3% were foreign born.