Walters Ranch Hop Kiln is historical site of buildings built in 1905, in Sonoma, California in Sonoma County, California. The Walters Ranch Hop Kiln is a California Historical Landmark No. 627 listed on January 13, 1958. The Walters Ranch Hop Kiln was built by Italian stonemason, Angelo "'Skinny" Soldini. Sol Walters purchased 380 acres of the Rancho Sotoyome, a 1853 Mexican land grant to Josefa Fitch. The Walters Ranch Hop Kiln is composed of three stone kilns (ovens, Oast houses) for drying hops for 20 hours a patch. Hops are used in beer making breweries. In addition to the kilns, the site as a wooden building for cooling the hops and a two-story press for baling the hops for shipment. The Walters Ranch Hop Kilns was one of early and large operation in the Northern California region.

Landmark Vineyards purchased the property in 2016. Landmark Vineyards', Landmark Hop Kiln Winery, is restoring the buildings that are in the Russian River Valley. It was hops, not grapes that was Sonoma County's first major crop. By 1940 hops was no longer and major crop due to the downy mildew disease and insect phylloxera.

There are other historical buildings on the site, A 1888 sheep barn was built with square nails and wood peg construction. Also a Italianate house.

A California historical marker is at 6050 Westside Road, Healdsburg. The historical marker at Walters Ranch Hop Kiln was placed there by the California Department of Parks and Recreation in working with the Griffin Vineyard on May 1, 1977.

Walters Ranch Hop Kiln is on the National Register of Historic Places in Sonoma County, California.

• California Historical Landmarks in Sonoma County