Menlo Park, CA has a population of 33,319 and is the 1,278th largest city in the United States. The population density is 3,335 per sq mi which is 1335% higher than the California average and 3581% higher than the national average. The median age in Menlo Park is 36 which is approximately 1% higher than the California average of 36. In Menlo Park, 59% of the population over 15 years of age are married, 69% speak English and 14% speak Spanish. 45% of Menlo Park residents were born in California, 28% were born out of state, 2% were born outside of the United States and 24% were foreign born.