Inverness is an unincorporated community and census-designated place (CDP) in western Marin County, California, United States. It is located on the southwest shore of Tomales Bay 3.5 miles northwest of Point Reyes Station and about 40 miles (65 km) by road northwest of San Francisco, at an elevation of 43 feet. In the 2020 census, the population was 1,379. The community was named by a Scottish landowner after Inverness in Scotland.

Tomales Bay is a long, narrow inlet of the Pacific Ocean in Marin County in northern California in the United States. It is approximately 15 mi (24 km) long and averages nearly 1.0 mi (1.6 km) wide, effectively separating the Point Reyes Peninsula from the mainland of Marin County. It is located approximately 30 mi (48 km) northwest of San Francisco. The bay forms the eastern boundary of Point Reyes National Seashore. Tomales Bay is recognized for protection by the California Bays and Estuaries Policy. On its northern end, it opens out onto Bodega Bay, which shelters it from the direct current of the Pacific. The bay is formed along a submerged portion of the San Andreas Fault.