Williamsburg, NM has a population of 451 and is the 20,180th largest city in the United States. The population density is 932 per sq mi which is 5339% higher than the New Mexico average and 929% higher than the national average. The median age in Williamsburg is 41 which is approximately 11% higher than the New Mexico average of 37. In Williamsburg, 56% of the population over 15 years of age are married, 94% speak English and 6% speak Spanish. 45% of Williamsburg residents were born in New Mexico, 51% were born out of state, 0% were born outside of the United States and 4% were foreign born.