Eureka, California Zip Codes
📍 Eureka is in Humboldt County, California with 3 zip codes; the most populous is 95503.
Eureka is a USPS city name in Humboldt County, California with a Census population of approximately 47,778 across its ZIP codes. Humboldt County as a whole has 38 ZIP codes in this directory. Below you'll find every zip code serving Eureka with population, income and home value, a map, and the city's affordability profile.
Population and demographic data sourced from the U.S. Census Bureau American Community Survey (ACS) 5-Year Estimates. ZIP code routing data sourced from the United States Postal Service (USPS).
All Eureka Zip Codes
Eureka at a Glance
Eureka has 3 ZIP codes in this directory: 2 standard delivery ZIPs and 1 PO Box or unique ZIP that carries no resident population in Census data. The 2 ZIPs with published Census housing data cover 47,778 residents, the largest being 95503 with 24,072 people.
The median ZIP in Eureka has a household income of $60,265 and a home value of $369,850, a price-to-income ratio of 6.2, below the 6.7 California ZIP median. The highest median income is in 95503 at $68,307. Median rent across these ZIPs is $1,206 a month.
58% of households in the typical Eureka ZIP own their home (statewide ZIP median 64%). 31% of adults hold a bachelor's degree, in line with the 31% statewide median. The median poverty rate is 18.7%, far above the 10.8% statewide ZIP median. Overall density is about 525 residents per square mile across 91 square miles of ZIP land area.
Medians are taken across the ZIP codes listed below (each ZIP weighted equally); PO Box and no-data ZIPs are excluded. Definitions on the methodology page; statewide comparisons in the 2026 California ZIP Code Affordability Report.
Eureka Zip Code Map
Interactive map of Eureka, California zip codes. Click any marker for details.