The terms California Impressionism and California Plein-Air Painting describe the large movement of 20th century artists who worked out of doors, directly from nature in California, United States. Their work became popular in the San Francisco Bay Area and Southern California in the first three decades after the turn of the 20th century. Considered to be a regional variation on American Impressionism, the California Impressionists are a subset of the California Plein-Air School.

American Impressionism was a style of painting related to European Impressionism and practiced by American artists in the United States from the mid-nineteenth century through the beginning of the twentieth. The style is characterized by loose brushwork and vivid colors with a wide array of subject matters but focusing on landscapes and upper-class domestic life.