Hexavalent chromium (Cr(VI)) is an extremely toxic and mobile pollutant produce from tannery, electroplating and textile effluents, and sustainable remediation strategies are required to comply with strict environmental standards (e.g. WHO: 0.05 mg/L in drinking water). This chapter elaborates in detail about bioadsorption as an eco-friendly cost-effective method of Cr(VI) removal from aqueous solutions using renewable bioadsorbents consisting of agricultural byproducts (e.g. rice husk, walnut shells), microbial biomass (bacterial, fungal, algal), chitosan derivatives and biochar derived from biomass. The chemistry of Cr(VI) speciation (HCrO₄− at pH 1–6, CrO₄2− at pH > 7) and toxicity are the basis for the design of bioadsorption processes comprising ion exchange, electrostatic attraction, surface complexation and reductive transformation to Cr(III) supplemented with bioaccumulation in living cells. Advanced bioadsorbent modifications—chemical activation (e.g. citric acid, NaOH), nanocomposites (e.g. magnetite-chitosan), ternary nanoadsorbents (Fe₂O₃-MnO₂-SnO₂), green synthesis have improved the adsorption capacity reaching 100–315 mg/g, which is higher than many synthetic adsorbents. Factors affecting the efficiency such as pH (optimal 2–3), initial Cr(VI) concentration, bioadsorbent dosage, contact time (60–250 min until equilibrium), temperature and effect of competing ions (SO₄2−, NO₃−), are modelled using Langmuir, Freundlich, Temkin and Redlich-Peterson isotherms, using pseudo-second-order kinetics and intra-particle diffusion identify chemisorption domination. Real world applications in wastewaters from tanneries and electroplating evident that removal of Cr(VI) of 90–99%, with continuous systems and regeneration (80–95% recovery over 5–10 cycles) refining practicality, as shown by specific trials with tannery effluent. Synchrotron-based techniques (e.g. XANES, EXAFS) and FTIR/XPS analyses help to understand the Cr binding and reduction processes, whereas the techno-economic analyses reinforce the scale-up feasibility. Challenges such as low native capacities (< 50 mg/g), pH sensitivity and spent bioadsorbent disposal—are being overcome by such emerging trends as hybrid technologies (bioadsorption-photocatalysis), genetic engineering of a microbial consortia, microbiome engineering for synergistic effects, artificial intelligence for optimisation processes and circular economy approaches valorising spent biomass into biofertilisers. The chapter concludes by promoting the need for pilot-scale validation and policy-driven involvement of the community to realise the transformative potential of bioadsorption for Cr(VI) remediation.