Callahan is an unincorporated community in Siskiyou County, California, United States. Callahan is located on California State Route 3 11.5 miles south-southeast of Etna. Callahan has a post office with ZIP code 96014. The post office opened as Callahan's Ranch in 1858 and changed its name to Callahan in 1892. The community was named after M.B. Callahan, who opened a travelers' stop in the community in 1851.On January 6, 1947, school children at Callahan's one room schoolhouse were greeted by the body of a dead African American man, strung up from a nearby telephone pole. A calfskin was wrapped around his shoulders and he was riddled with bullet holes. The January 10, 1947 edition of the Western Sentinel newspaper carried a front page story about the lynching, identifying the man as a butcher from Weed, California. The January 12, 1947 edition of the Etna Gazette also carried the story.