Los Alamitos, CA has a population of 11,661 and is the 3,494th largest city in the United States. The population density is 2,900 per sq mi which is 1033% higher than the California average and 3100% higher than the national average. The median age in Los Alamitos is 40 which is approximately 12% higher than the California average of 36. In Los Alamitos, 54% of the population over 15 years of age are married, 78% speak English and 10% speak Spanish. 63% of Los Alamitos residents were born in California, 21% were born out of state, 2% were born outside of the United States and 14% were foreign born.