Forestville is a census-designated place (CDP) in Sonoma County, California, United States. It was settled during the late 1860s and was originally spelled Forrestville after one of its founders. The spelling long ago became standardized with one "r". The population was 3,293 at the 2010 census, an increase of nearly 1,000 since the 2000 census.

The Russian River is a southward-flowing river that drains 1,485 sq mi (3,850 km2) of Sonoma and Mendocino counties in Northern California. With an annual average discharge of approximately 1,600,000 acre feet (2.0 km3), it is the second-largest river flowing through the nine-county Greater San Francisco Bay Area, with a mainstem 115 mi (185 km) long.