Water pollution caused by heavy metals poses a serious threat to the ecosystem and human survival safety and becomes a major obstacle to human health, economic and socially sustainable development. Among the various treatment techniques for water remediation, adsorption is an efficient method due to its high capacity, low cost, and simplicity. Thallium (Tl) is highly toxic to mammals and its removal from water is gaining increasingly prominent attention. In this study, three fungal strains (Fusarium sp. FP, Arthrinium sp. FB and Phoma sp. FR) were tested for removal of Tl(I) from an aqueous solution and showed excellent removal performance. The prepared inactive fungal strains were characterized by XRD, FT-IR, SEM, and XPS analysis. The effects of pH, contact time, biomass and reaction temperature on the removal efficiency of Tl(I) were systematically investigated. The results indicated that the adsorption isotherm data fit well with the Langmuir model, and the pseudo-second-order model was more consistent with the kinetic data description. The maximum adsorption capacity of the fungal strain (Fusarium sp. FP, Arthrinium sp. FB and Phoma sp. FR) for Tl(I) was found to be 94.69 mg/g, 66.97 mg/g and 52.98 mg/g, respectively. The thermodynamic data showed that the sorption process was spontaneous and endothermic. The present study showed that the inactive fungal strains could be a promising adsorbent material for Tl(I) removal.