Sewage and sludge characterisation is essential to comprehending their effects on the environment and improving treatment procedures. The physical, chemical, and biological characteristics of sewage and the accompanying sludge produced during wastewater treatment are the main subjects of this research. A number of parameters were examined, including pH, temperature, total suspended solids (TSS), chemical and biological oxygen demands (BOD and COD), nutrients (phosphorus and nitrogen), heavy metals, and microbial composition. The findings show that the composition varies significantly according on whether the sewage comes from a mixed, industrial, or residential source. The high organic content, nutritional richness, and possible pollutants, such as harmful metals and pathogenic bacteria, were noted during sludge characterisation. These results are essential for choosing the best treatment methods, guaranteeing secure disposal or reuse, and lowering environmental and public health hazards. The research emphasises how crucial thorough characterisation is to promoting resource recovery and sustainable wastewater treatment techniques.