Oceano (Spanish: Océano, meaning "Ocean") is a census-designated place (CDP) in San Luis Obispo County, California, United States.

Activities on this beach include riding the sand dunes on all-terrain-vehicles, swimming, clamming, camping, surfing, surf fishing, hiking, and bird watching.

The ethnic makeup of Oceano was 5,105 (70.1%) White, 62 (0.9%) African American, 120 (1.6%) Native American, 165 (2.3%) Asian, 7 (0.1%) Pacific Islander, 1,509 (20.7%) from other races, and 318 (4.4%) from two or more races.

The racial makeup of the CDP was 68.73% White, 1.12% African American, 1.29% Native American, 1.80% Asian, 0.03% Pacific Islander, 21.78% from other races, and 5.25% from two or more races.

The environs of Oceano were the home of "Halcyon," a utopian religious community established in 1903 by the theosophical Temple of the People, based in Syracuse, New York.

[7] The group, which believed in channeling unseen electromagnetic forces in an effort to attain human perfection, constructed a number of buildings in association with their colonizing effort, including the Blue Star Memorial Temple and the Halcyon Hotel and Sanatorium.

[7] In 1948, Oceano, was the site of the founding by Catherine Nimmo (a registered nurse and Doctor of Chiropractic who had recently moved there from the Netherlands[8]) and Rubin Abramowitz (an engineer) of the U.S. Vegan Society, the first vegan society in the United States.

[12] The Oceano Community Services District provides the following services: fire and emergency, water, wastewater collection, solid waste, parks and recreation, and limited street lighting.

As an unincorporated town in San Luis Obispo County, Oceano is in the Board of Supervisors 4th District.

In the state legislature Oceano is in the 17th Senate District, represented by Democrat John Laird, and in the 35th Assembly District, represented by Democrat Jasmeet Bains.