Explore Mill Valley local geography, civic resources and voter guides, with dated official population and registration facts for Marin County.
At a glance: Mill Valley is an incorporated city in Marin County. Population: 13,694 (California Department of Finance estimate as of January 1, 2026). Registered voters: 10,799 (California Secretary of State, as of September 4, 2026).
Mill Valley occupies wooded valleys and lower slopes on the southeastern side of Mount Tamalpais. Its landscape shifts from redwood-shaded downtown streets to open bayfront areas near Richardson Bay. Boyle Park supplies courts, play areas, and ballfield space, while Bayfront Park connects recreation with the shoreline. Mill Valley Public Library and the Community Center provide complementary indoor civic resources. Mill Valley incorporated on September 1, 1900. It is a general-law city with a council-manager government, distinct from nearby unincorporated communities that may use Mill Valley mailing addresses.
Bayfront Park provides shoreline-oriented walking and recreation space off Sycamore Avenue.
Boyle Park has tennis courts and a playground; the city's parks page notes that tennis passes are required.
No. Some nearby communities are unincorporated. Check your address against municipal boundaries before relying on city services or city ballot eligibility.
10,799 (California Secretary of State, as of September 4, 2026).
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