The San Mateo County Harbor District is an autonomous district created to operate harbor facilities within the boundaries of San Mateo County.

The San Mateo County Harbor District was founded as an autonomous district with jurisdiction to operate within the borders of San Mateo County by a 1933^[1] resolution of the San Mateo County Board of Supervisors. That action was pursuant to the June 10, 1931 creation by the California State Legislature of an “Act Providing for the Formation, Government and Operation of Harbor Districts, the Calling and Conducting of Elections in such District of Harbor Commissioners, defining their powers and duties, and providing for the issuance and disposal of bonds of such Harbor District, and providing for the assessment, levy, and collection of taxes for the payment of such bond and for the ordinary annual expenses of such Harbor District."^[2][3] The district remained inactive until 1948.^[4]

The Harbor District operates two facilities: Pillar Point Harbor in Princeton on the Pacific Ocean coast just north of Half Moon Bay and the Oyster Point Marina/Park on the San Francisco Bay in the City of South San Francisco. The City of South San Francisco owns Oyster Point Marina/Park and the Harbor District operates it on behalf of the City under a Joint powers authority agreement. Pillar Point is a working fishing harbor with 369 berths. and Oyster Point is a 600 berth recreational boating marina.

The Harbor District is governed by a five-member Board of Harbor Commissioners, who are elected in Districted elections for staggered four-year terms.

Meetings of the SMHCD are published to the District's YouTube channel, Pacific Coast TV YouTube channel, and are also broadcast live on local cable television.