Greenfield, CA has a population of 16,994 and is the 2,523rd largest city in the United States. The population density is 7,955 per sq mi which is 3323% higher than the California average and 8681% higher than the national average. The median age in Greenfield is 26 which is approximately 29% lower than the California average of 36. In Greenfield, 52% of the population over 15 years of age are married, 18% speak English and 79% speak Spanish. 53% of Greenfield residents were born in California, 4% were born out of state, 1% were born outside of the United States and 42% were foreign born.