Dwindling petroleum resources and increasing environmental concerns have stimulated the production of platform chemicals via biochemical processes through the use of renewable carbon sources. Various types of biomass wastes, which are biodegradable and vastly underutilized, are generated worldwide in huge quantities. They contain diverse chemical constituents, which may serve as starting points for the manufacture of a wide range of valuable bio-derived platform chemicals, intermediates, or end products via different conversion pathways. The valorization of inexpensive, abundantly available, and renewable biomass waste could provide significant benefits in response to increasing fossil fuel demands and manufacturing costs, as well as emerging environmental concerns. This review explores the potential for the use of available biomass waste to produce important chemicals, such as monosaccharides, oligosaccharides, biofuels, bioactive molecules, nanocellulose, and lignin, with a focus on commercially viable technologies.