A light-weight and electromagnetic interference (EMI) shielding conductive epoxy resin (EP) composite foam was firstly fabricated by loading nickel coated carbon fibers (NCCFs). The foamed EP/NCCFs composites with a uniform foam cell containing various NCCFs contents (0–5.03 vol%) have been fabricated via chemical foaming. The foams exhibit densities of as low as 0.45 g cm− 3. Owning to the high aspect ratio of carbon fibers and selective distribution of NCCFs in the foam structure, NCCFs could easily connect with each other and construct the conductive network in polymer matrix. As a result, the composite foams exhibit an EMI shielding effectiveness of ~33 dB and a corresponding specific EMI shielding effectiveness of as high as 77.4 dB cm3 g− 1 in the microwave frequency range of 8.2–12.4 GHz. Such composite foam would be considered as a promising lightweight and EMI shielding material in aerospace and electronics.