Lennox, CA has a population of 21,963 and is the 1,983rd largest city in the United States. The population density is 20,089 per sq mi which is 8544% higher than the California average and 22073% higher than the national average. The median age in Lennox is 29 which is approximately 20% lower than the California average of 36. In Lennox, 47% of the population over 15 years of age are married, 10% speak English and 87% speak Spanish. 52% of Lennox residents were born in California, 2% were born out of state, 1% were born outside of the United States and 45% were foreign born.