Mount Eddy is the highest peak of the Trinity Mountains, a mountain range of the Klamath Mountains System, located in Siskiyou County, and Trinity County in northern California. The mountain is in the Mount Eddy RNA, a Research Natural Area on the Shasta–Trinity National Forest, a unit of the United States Forest Service. The mountain is composed of mesozoic ultramafic rock, predominantly serpentinized peridotite.