Walnut, California Zip Codes
📍 Walnut is in Los Angeles County, California with 3 zip codes; the most populous is 91789.
Walnut is a USPS city name in Los Angeles County, California with a Census population of approximately 41,377 across its ZIP codes. Los Angeles County as a whole has 538 ZIP codes in this directory. Below you'll find every zip code serving Walnut 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 Walnut Zip Codes
Walnut at a Glance
Walnut has 3 ZIP codes in this directory: 1 standard delivery ZIP and 2 PO Box or unique ZIPs that carry no resident population in Census data. The 1 ZIP with published Census housing data cover 41,377 residents, the largest being 91789 with 41,377 people.
The median ZIP in Walnut has a household income of $123,555 and a home value of $910,400, a price-to-income ratio of 7.4, above the 6.7 California ZIP median. Median rent across these ZIPs is $2,690 a month.
82% of households in the typical Walnut ZIP own their home (statewide ZIP median 64%). 53% of adults hold a bachelor's degree, far above the 31% statewide median. The median poverty rate is 7.2%, below the 10.8% statewide ZIP median. Overall density is about 2,602 residents per square mile across 16 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.
Walnut Zip Code Map
Interactive map of Walnut, California zip codes. Click any marker for details.