Nubieber is a census-designated place in Lassen County, California. It is located at the common terminus of the Western Pacific Railroad and the Great Northern Railway Bieber Line 3 miles southwest of Bieber, at an elevation of 4121 feet. Its population is 19 as of the 2020 census, down from 50 from the 2010 census. The settlement was established in 1931, when the railroads were built to the place. The first post office opened the same year. The name was a version of "New Bieber".