In the present paper, a natural bentonite (B) has been modified with a cationic surfactant hexadecyltrimethylammonium bromide (OB) and then encapsulated into calcium alginate to prepare a novel organobentonite composite beads (A-OB), in order to remove a Congo Red (CR) dye from aqueous solution, using a batch adsorption process. The A-OB beads were characterized using FTIR, SEM, and pHPZC analysis. The performance of the obtained composite beads through the removal of the CR dye was evaluated by the effect of the following parameters: initial dye concentration (25-300 mg L-1), contact time (5-1700 min) and temperature (10-40 C). A kinetic study indicated that adsorption was governed by the pseudo-second order kinetic equation and that the adsorption process is best described by Langmuir isotherm model. The results showed that the maximum adsorption capacity (qmax) of A-OB composite beads was 218 mg g-1. Furthermore, thermodynamic studies showed spontaneous and exothermic nature of the overall adsorption process. The regeneration study confirmed that the present composite beads can be regenerated up to fifth cycle successfully. The results indicate that alginate-organobentonite composite beads are efficient adsorbents and could be used as a low-cost material for the removal of Congo Red anionic dyes from wastewater.