The Coast Miwok are an Indigenous people of California that were the second-largest tribe of the Miwok people. Coast Miwok inhabited the general area of modern Marin County and southern Sonoma County in Northern California, from the Golden Gate north to Duncans Point and eastward to Sonoma Creek. Coast Miwok included the Bodega Bay Miwok, or Olamentko (Olamentke), from authenticated Miwok villages around Bodega Bay, the Marin Miwok, or Hookooeko (Huukuiko), and Southern Sonoma Miwok, or Lekahtewutko (Lekatuit). While they did not have an overarching name for themselves, the Coast Miwok word for people, Micha-ko, was suggested by A. L. Kroeber as a possible endonym, keeping with a common practice among tribal groups and the ethnographers studying them in the early 20th Century and with the term Miwok itself, which is the Central Sierra Miwok word for people.

Marin County is located in the northwestern part of the San Francisco Bay Area of the U.S. state of California. As of the 2020 census, the population was 262,231. Its county seat and largest city is San Rafael. Marin County is across the Golden Gate Bridge from San Francisco, and is included in the San Francisco–Oakland–Berkeley, CA Metropolitan Statistical Area.