Snell Valley is a depression landform in Napa County, California.

[1] This feature is located approximately five miles north of Aetna Springs.

An example of wildflowers in Snell Valley is Gold Nuggets, Calochortus luteus.

It is assumed that the valley is named after George and Hiram Snell, two brothers from Germany, who were documented as residents of the Guenoc Rancho in 1857.

[3] In August 2020, Snell Valley was evacuated due to the Hennessey Fire, which burned of over 315,000 acres (127,476 ha) in five counties, including in Snell Valley.