This book investigated melt-blown fibers' production methods and applications for sustainable and green composite production. Firstly, the melt-blown fiber formation mechanism was investigated, considering the effect of processing parameters on the fiber mat properties. And then, a new concept of making advanced single-polymer composites with melt-blown fiber mat interleaving was demonstrated. The effect of melt-blown fiber mat interleaving on the composite laminae’s thermal and mechanical behavior was evaluated. The multiwalled carbon nanotube-doped polypropylene melt-blown fiber mats were produced, and the effect of multiwalled carbon nanotube doping on thermal and mechanical properties was analyzed. Carbon nanotube-doped melt-blown fiber mats were also used as an interleaving veil to produce single-polymer composites. The effect of the nanocomposite fiber mat on the single-polymer composite’s thermal and mechanical characteristics was also detailed. In this chapter, results from these experimental studies were summarized, and significant findings were highlighted. Furthermore, the past and future of melt blowing research and development were briefly discussed. New concepts and future directions of melt-blown fibers and their composites were discussed in light of the sustainable industrial revolution goals.