Los Angeles County (FIPS 06037): Data Profile

Los Angeles County (FIPS 06037) is the most populous county in the United States, with approximately 10 million residents — more than the population of most US states. It's also the economic core of the Los Angeles-Long Beach-Anaheim Metropolitan Statistical Area, the nation's second-largest metro. For data professionals, LA County is one of the most frequently analyzed geographies in any federal dataset.

The FIPS code 06037 breaks down as: state 06 (California) + county 037. At roughly 4,000 square miles, LA County is geographically large — larger than Rhode Island and Delaware combined — and extremely diverse. It spans dense urban cores (Downtown LA, Hollywood), sprawling suburbs (the San Fernando Valley, the SGV), beach cities, and mountainous areas. This internal diversity makes county-level statistics a blunt instrument; sub-county Census tract analysis is often necessary to capture meaningful variation.

In federal datasets, LA County 06037 is among the most heavily weighted geographies in any national average. In the ACS, it contributes approximately 3% of the total US population to any national estimate. In BLS QCEW employment data, LA County's entertainment, logistics, and manufacturing sectors make it a case study for industry concentration. The county has among the highest absolute numbers of both poverty and wealth in any single county — median income statistics mask enormous internal variation.

The Los Angeles MSA code (31080) covers LA and Orange counties, while the broader Combined Statistical Area encompasses Riverside, San Bernardino, and Ventura counties as well. For analysis spanning the full Southern California mega-region, you need either MSA-level data or the individual county FIPS codes for all component counties. See the full LA County data profile, browse California's county list, or use the search tool to find the codes you need.