Adsorption is a prominent and cost-effective water treatment method that has been used to remove a variety of contaminants due to its efficacy, ease of use, and environmental friendliness. Biosorbents developed from agricultural wastes have been extensively studied. This review gives insight into the potential of carbonaceous coconut shells as a source of biomass material to prepare adsorbents for wastewater treatment. The feasibility of coconut shells as a precursor material is beneficial for extensive industrial-scale applications due to their natural properties and long-term availability. This review article also illustrates the excellent adsorption performance of adsorbents derived from coconut shells that can be an alternative precursor to commercial carbons with a high market price. This review points out the applications of coconut shell-based adsorbents in removing a wide range of contaminants and actual industrial wastewater. Additionally, literature shows that modified coconut shell-based adsorbents show better adsorption performance in removing hazardous pollutants due to enhancement in adsorbents’ structural characteristics. The discussion on the environmental and economic perspectives on utilizing coconut shell-based adsorbents is also of the highlights of this review. It is prospective for industries to explore converting agricultural wastes into low-cost green adsorbents for wastewater treatment.