Lake Success, NY has a population of 3,084 and is the 8,670th largest city in the United States. The population density is 1,673 per sq mi which is 366% higher than the New York average and 1747% higher than the national average. The median age in Lake Success is 50 which is approximately 32% higher than the New York average of 38. In Lake Success, 72% of the population over 15 years of age are married, 53% speak English and 2% speak Spanish. 54% of Lake Success residents were born in New York, 11% were born out of state, 2% were born outside of the United States and 34% were foreign born.