Water pollution has become a major environmental problem globally. Different types of contaminants and dyes discharged from the textile industries significantly contribute to water pollution. These dyes are not only harmful to plants and aquatic life, but also to human beings. In this regard, pearl millet stalk (Pennisetum glaucum), a lignocellulosic material, has been explored for the adsorption of dyes from a synthetic textile dye effluent consisting of an equal mixture of five textile dyes. It is an inexpensive and abundantly available sustainable waste material in many states of India, usually discarded after crop harvesting. The fibres were extracted from pearl millet stalk (PMS) at optimised conditions and used for the adsorption and desorption studies. The effect of initial dye concentration (10–300 mg/L), adsorbent size (1–10 mm), adsorbent dose (0.25–3 g/50 mL), pH, temperature (20–60 °C) and time were investigated. The applicability of Langmuir and Frendluich isotherm was also examined. At a highest concentration of 300 mg/L, one gram of PMS fibre can remove 75% dye from synthetic effluent at a particle size of 2.3 mm at pH 3 and temperature 20 °C. The desorption efficiency of dye-adsorbed PMS fibres was also studied at different pH and it was found that the highest desorption occurs at pH 12. The results indicate that PMS fibres could be a potential sustainable alternative material with respect to costly and synthetic adsorbents used for dye removal.