The paper presents the results of the cesium sorption from seawater with commercially available sorbents (Anfezh, Niket, Uniket, FSS, FD-M, Axionit RCs, Termoxid 35, Termoxid 3A, NKF-C) under the batch and flow conditions, including the distribution coefficients of ¹³⁷Cs, the dynamic exchange capacity and the total dynamic exchange capacity of the sorbents for cesium as well as the output curves of cesium sorption at different flow rates of the seawater. The data obtained makes it possible to select the most effective sorbents for concentrating and analyzing radiocesium in seawater. Some of the sorbents are effective for ¹³⁷Cs sorption from seawater. The maximum distribution coefficients of ¹³⁷Cs under the batch conditions are more than 6 × 10⁴ mL g⁻¹ for the sorbents Anfezh and FD-M. The maximum values of the total dynamic exchange capacity in the process of the non-radioactive cesium sorption for the Uniket and Niket sorbents are 77.7 and 88.8 mg g⁻¹, respectively.