Lake Darby, OH has a population of 4,392 and is the 7,016th largest city in the United States. The population density is 1,268 per sq mi which is 392% higher than the Ohio average and 1300% higher than the national average. The median age in Lake Darby is 35 which is approximately 10% lower than the Ohio average of 39. In Lake Darby, 70% of the population over 15 years of age are married, 91% speak English and 3% speak Spanish. 74% of Lake Darby residents were born in Ohio, 20% were born out of state, 0% were born outside of the United States and 6% were foreign born.