<p>Solid acids and super-acids have been the subjects of continued interest due to their numerous applications in many chemical and pharmaceutical industries. They are claimed to be responsible for producing more than 1 × 10⁸ metric tons of products per year. In recent times, in particular, inorganic solid acid-catalyzed organic synthesis and transformation reactions have gained more attention due to the proven advantage of heterogeneous catalysts, simplified product isolation, mild reaction conditions, high selectivity, ease in recovery and reuse of the catalysts, and reduction in the generation of wasteful side products. In that context, we were interested in investigating various industrially important organic reactions to replace toxic and corrosive reagents, noxious or expensive solvents, and multistep processes with single-step and solvent-free ones by employing environmentally benign solid acid catalysts. The primary objective of this mini-review is to summarize the recent developments in biomass-based organic synthesis and transformation reactions of commercial significance catalyzed by WO_x/ZrO₂ green solid acid catalysts. The preparation of catalysts and their characterization are briefly discussed, emphasizing the application of these catalysts for a variety of practical reactions.</p>