Sources covering the entire United States
Census of Population and Housing and related demographic sources
American Factfinder (Census Bureau) provides official Census of Population and Housing 2010 data at the Zip Code level online.
MCDC Demographic Profiles, 2010 Census (Missouri State Census Data Center). Generate a Zip Code level demographic profile based on Census 2010 sample data.
Community Sourcebook of Zip Code Demographics, a print source with demographic and marketing variables.
ZIP Code Statistics (Census Bureau). Census Bureau products that offer Zip Code level information, many of which are for sale.
Yahoo! Real Estate Neighborhood Profiles Includes demographics, cost of living, housing characteristics and selected quality of life data by Zip Code.
ZIPskinny. Provides basic demographic data from Census 2010 and comparisons with nearby Zip Codes.
Demographics USA. ZIP Edition a print source with demographic and marketing variables.
Quality of Life in American Neighborhoods : Levels of Affluence, Toxic Waste, and Cancer Mortality in Residential Zip Code Areas. Print source published in 1986 includes selected population data from the 1980 Census of Population and Housing by Zip Code as well as toxic waste information.
Sources covering California only
Birth and Death Profiles by Zip Code (California Department of Public Health). Most recent statistics and links to more than a decade of older data.
Rand California (Oviatt Library subscription).