Waste biomass has immense potential to serve as a significant renewable energy source depending on its composition and processing methods. It includes agricultural residues, forestry wastes, industrial wastes, animal manure, municipal solid waste, algal biomass, sewage sludge, etc., each of which shows varying energy potentials ranging from 5 to 25 ML/kg depending upon their characteristics like proximate and ultimate analysis and their suitability for biomass production. Advancements in methods like microbial engineering for biodegradation, genetic modification of enzymes, and synthetic biology approaches in biofuel production have shown immense potential in harnessing bio-energy and making them promising sources of renewable energy generation. Emerging trends in waste-to-energy bioengineering processes include microbial consortia and bioelectrochemical systems for enhanced bioconversion. AI and ML are also extensively being utilized as advancements in bioengineering processes. The potential of various waste biomass sources and their respective energy conversion pathways is crucial for advancing a circular bioeconomy. Future research should focus on optimizing conversion technologies and scaling up bioenergy production for broader industrial applications.