Previous studies showed that Chlorella vulgaris microalgae (Chlorophyta) possessed high physiological activity as a biosorbent for rare-earth elements (REE), and in this study, the sorption capacity for both La3+ and Sm3+ was demonstrated. The microalgae cells were immobilized onto calcium alginate gel aiming at its use in the recovery and separation of studied REE. The biosorption tests were conducted in batch using an incomplete factorial design, and the residual concentrations of REE were determined using ICP-OES. Contact time was the variable that positively influenced La3+ biosorption, while the temperature variable showed a positive effect only on the biosorption of Sm3+. Thus, the evaluated conditions seem to present selectivity for separating light REE and heavy REE and may allow the development of a REE separation process on a larger scale based on the biosorption process. This is thought to be the first report on utilization of immobilized C. vulgaris cells as a candidate for the bioseparation of REE from diluted liqueurs.