Zenia is an unincorporated community in Trinity County, California, United States. Zenia is 6.5 miles (10.5 km) northeast of Alderpoint. Zenia has a post office with ZIP code 95595, which opened in 1899. Zenia was first named 'Poison Camp' by men who went there in the 1860s after larkspur in the area which poisoned their cattle. Postmaster George Croyden named the community Zenia after a girl.