India, a leading leather producer with over 3000 tanneries—70% of which are in Tamil Nadu—treats tannery effluent through individual or common effluent treatment plants (CETPs). Secondary treated wastewater is further processed using membrane systems for water recovery and reuse. Following the adoption of Zero Liquid Discharge (ZLD) technology, many tanneries have implemented reverse osmosis (RO) for water recovery followed by multiple-effect evaporation (MEE), resulting in a residue of salts and other materials stored in CETPs. Disposal of this solid residue poses a significant threat to the environment. As the solid residue mainly contains inorganic salts and organic matter, resource recovery can help manage this waste and make the process sustainable and cost-effective. This study addresses the treatment of solid residue from tanneries’ CETPs by presenting sustainable processes for minimizing waste and recovering sodium chloride (NaCl), sodium sulphate (Na2SO4) and gypsum (CaSO4·2H2O). Two process configurations have been designed to valorize the solid waste to recover added-value products. An alternative process is also developed to modify ZLD process with enhanced separation and recovery of salts with a better composition for potential commercial use. Utilizing solid residues can contribute to the circular economy by minimizing waste and promoting resource recovery. As tanneries explore these options, they can also improve their public image and meet growing consumer demand for environmentally responsible practices. Overall, the combined efforts of the industry and regulatory bodies can lead to significant advancements in sustainable practices within the leather sector.