Oak Park, CA has a population of 14,885 and is the 2,850th largest city in the United States. The population density is 2,813 per sq mi which is 1111% higher than the California average and 3005% higher than the national average. The median age in Oak Park is 42 which is approximately 16% higher than the California average of 36. In Oak Park, 64% of the population over 15 years of age are married, 78% speak English and 4% speak Spanish. 53% of Oak Park residents were born in California, 28% were born out of state, 1% were born outside of the United States and 17% were foreign born.