Waldo, KS has a population of 44 and is the 28,301st largest city in the United States. The population density is 117 per sq mi which is 234% higher than the Kansas average and 29% higher than the national average. The median age in Waldo is 66 which is approximately 81% higher than the Kansas average of 36. In Waldo, 87% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 70% of Waldo residents were born in Kansas, 30% were born out of state, 0% were born outside of the United States and 0% were foreign born.