Mill Valley California ZIP Codes

Mill Valley 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We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP.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 Mill Valley codes above are listed without a column we would have to invent.

Scope every ZIP code recorded for Mill Valley. 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 Mill Valley ZIP code begins 949. Those first three digits identify the sectional center facility that processes mail for this part of California. Statewide that range covers 55 ZIP codes, so Mill Valley accounts for 4% 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 Mill Valley occupies.

• 415 Area code 415
• 628 Area code 628

Mill Valley California area codes in full →

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