Over the past two decades, the advancements of nanotechnology, particularly nanomaterials science, have produced a broad range of nanomaterials (NMs) that include nanofibers (NFs), nanoparticles (NPs), nanorods (NRs), and nanowires (NWs), which have been technically and practically examined over various applications. NFs have shown excellent potential for diverse applications in materials science, chemical industry, energy storage, and structural support due to a combination of remarkable properties such as high surface area, great electrical conductivity, and high mechanical stability. To date, a large number of mechanical and chemical synthetic methodologies (i.e., thermal-phase separation, electrospinning, pulling, self-assembly, and template processes) have been proposed to fabricate a new generation of NFs. In order to improve the performance of NFs, several functionalization steps have been proposed. The functionalization of NFs plays a prominent role in commercializing them on the industrial scale. In the current review article, recent progress in the fabrication and characterization of NFs is highlighted and reviewed to provide comprehensive methods on synthesizing a new generation of well-modified NFs with superior structural, physicochemical, and textural characteristics. In addition, the performance of synthesized NFs in a variety of practical applications, such as electrodes for fuel cells and lithium batteries, water and air purification, biomedicine, and catalysis, is reviewed.