San Luis, NM has a population of 39 and is the 28,419th largest city in the United States. The population density is 5 per sq mi which is 73% lower than the New Mexico average and 95% lower than the national average. The median age in San Luis is 74 which is approximately 99% higher than the New Mexico average of 37. In San Luis, 23% of the population over 15 years of age are married, 0% speak English and 100% speak Spanish. 100% of San Luis residents were born in New Mexico, 0% were born out of state, 0% were born outside of the United States and 0% were foreign born.