Greenfield CDP, CA has a population of 4,582 and is the 6,854th largest city in the United States. The population density is 3,441 per sq mi which is 1244% higher than the California average and 3698% higher than the national average. The median age in Greenfield CDP is 34 which is approximately 6% lower than the California average of 36. In Greenfield CDP, 57% of the population over 15 years of age are married, 51% speak English and 49% speak Spanish. 64% of Greenfield CDP residents were born in California, 12% were born out of state, 1% were born outside of the United States and 23% were foreign born.