Fairfield California ZIP Codes

Fairfield holds 2 ZIP codes, all inside one county and one postal prefix.

We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP. USPS delivery-type products are licensed, and no clean-rights source maps ZIP codes to neighbourhoods — so the Fairfield codes above are listed without a column we would have to invent.

Scope every ZIP code recorded for Fairfield. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. ZIP codes are delivery-route groupings, not areas; the boundaries implied by any ZIP map are approximations.

Every Fairfield ZIP code begins 945. Those first three digits identify the sectional center facility that processes mail for this part of California. Statewide that range covers 93 ZIP codes, so Fairfield accounts for 2% of it.

Every California ZIP prefix and the region it covers →

ZIP codes and area codes are separate systems — one routes mail, the other routes calls — and they do not share boundaries. The codes below serve the same ground Fairfield occupies.

• 341 Area code 341
• 369 Area code 369
• 510 Area code 510
• 707 Area code 707

Fairfield California area codes in full →

Straight-line distance between place reference points, not driving distance.