Its position along State Route 1 is about halfway between Los Angeles and San Francisco, each of those cities being roughly 230 miles (370 km) away.

Prehistorically, the local area was inhabited by the Chumash people, including a large village south of San Simeon at Morro Creek.

[4] The first European land exploration of Alta California, the Spanish Portolà expedition, traveled northwest along the coast in September 1769.

At Ragged Point, which is about 15 mi (24 km) past San Simeon, the party turned inland across the Santa Lucia Range.

The first Europeans to settle in the immediate area near the bay of San Simeon were Portuguese shore whalers under the command of Captain Joseph Clark (born Machado) from the Cape Verde Islands, around 1864.

[11] The name San Simeon also refers to some geologic structures of the area, particularly elements of the coastal Jurassic-age landforms and ophiolite rock formations.

[12] According to the United States Census Bureau, the census-designated place covers an area of 0.8 square miles (2.1 km2), all of it land.

[13] San Simeon and the Hearst Castle area has a mild warm-summer Mediterranean climate (Köppen Csb) that is moderated by its relative proximity to the Pacific coastline.

[14] For statistical purposes, the United States Census Bureau has defined San Simeon as a census-designated place (CDP).

[19] The wastewater treatment plant is operated by a private company under contract with the district.