Hydrothermal carbonization (HTC) of biomass to produce one-dimensional carbonmaterials with hierarchical pores is of significant importance. Here, we fabricatecomposites of MnOx-encapsulated multiporous carbon nanofibers (M-MCNFs)from naturally available carbohydrates through a dopamine-assisted HTC/templating process. The introduction of dopamine aids in the formation of themorphology of carbon nanofibers (CNFs) by enhancing the interactions betweenthe hard-templates and carbohydrates. The chosen cryptomelane hard-templates,which are superior to traditional hard-templates, are converted into Mn3O4 nanoparticlesembedded in multiporous CNFs (MCNFs), eliminating the need fortedious post deposition procedures to introduce redox active sites. Hence, theobtained hybrids with large surface areas, hierarchical pores, and unique structuresshow great potential in supercapacitors. This economic and sustainable strategypaves a new way for synthesizing MCNFs and metal oxide-encapsulated MCNFscomposites from biomass.