Blocksburg (formerly, Larrabee, Blocksburgh, Blockburger's and Powellville) is an unincorporated community in Humboldt County, California. It is located east-southeast of Weott, at an elevation of . The ZIP Code is 95514.
The Blocksburgh post office opened in 1877. The name was changed to Blocksburg in 1893, and was named for Benjamin Blockburger, a local merchant. Blocksburg at one time had hotels, saloons, doctor and dentist offices, and a variety of other businesses. The town declined after the Redwood Highway bypassed it upon its completion in 1920.