Resident Population in San Diego County, CA was 3269.97300 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in San Diego County, CA reached a record high of 3332.48300 in January of 2018 and a record low of 1357.85400 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in San Diego County, CA - last updated from the United States Federal Reserve on May of 2024.