Preston, MD has a population of 903 and is the 15,765th largest city in the United States. The population density is 1,668 per sq mi which is 252% higher than the Maryland average and 1741% higher than the national average. The median age in Preston is 35 which is approximately 10% lower than the Maryland average of 38. In Preston, 62% of the population over 15 years of age are married, 96% speak English and 0% speak Spanish. 69% of Preston residents were born in Maryland, 28% were born out of state, 0% were born outside of the United States and 3% were foreign born.