Display omitted •A broad overview of biochar/LDH-based materials in water purification is presented.•The potential of biochar/LDH for the uptake of pollutants is critically evaluated.•Adsorption mechanisms and regeneration capability of biochar/LDH are appraised.•The catalytic degradation of various pollutants by biochar/LDH is reviewed.•Challenges and prospects of biochar/LDH in water treatment are highlighted. Biochar/layered double hydroxide (LDH) composites have gained considerable attention in recent times as low-cost sustainable materials for applications in water treatment. This paper critically evaluates the latest development in applications of biochar/LDH composites in water treatment with an emphasis on adsorption and catalytic degradation of various pollutants. The adsorption of various noxious contaminants, i.e., heavy metals, dyes, anions, and pharmaceuticals onto biochar/LDH composites are described in detail by elaborating the adsorption mechanism and regeneration ability. The synergistic effect of LDH with biochar exhibited significant improvement in specific surface area, surface functional groups, structure heterogeneity, stability, and adsorption characteristics of the resulting biochar/LDH composites. The major hurdles and challenges associated with the synthesis and applications of biochar/LDH composites in water remediation are emphasized. Finally, a roadmap is suggested for future research to assure the effective applications of biochar/LDH composites in water purification.