Benicia, CA has a population of 27,780 and is the 1,543rd largest city in the United States. The population density is 2,152 per sq mi which is 826% higher than the California average and 2275% higher than the national average. The median age in Benicia is 44 which is approximately 23% higher than the California average of 36. In Benicia, 59% of the population over 15 years of age are married, 84% speak English and 6% speak Spanish. 62% of Benicia residents were born in California, 24% were born out of state, 1% were born outside of the United States and 12% were foreign born.