Santa Ana is the county seat and second most populous city in Orange County, California, and with a population of 324,528 at the 2010 census, Santa Ana is the 57th-most populous city in the United States.
Santa Ana is the county seat. Santa Ana is second most populous city in Orange County. Orange County is California. Santa Ana is the 57th-most populous city in the United States. This is with a population of 324,528 at the 2010 census.