The aim of this study is to evaluate the effects of double-side curved baffle on the sloshing effects of a spherical tank. In this study, numerical simulation was adopted using ANSYS CFX software. Two different cases of a double-side curved baffle were put into account in this simulation. Spherical tank with 0.55 m baffle height and 0.80 m baffle height were investigated under three filling levels, namely 30, 50 and 75. The outcome of the study shows that the peak sloshing pressure, the peak velocity, and the corresponding peak sloshing forces were observed as 9997.8 Pa, 9.94 m/s and 4.99 N respectively. These peak values correspond to baffle height of 0.55 m, with 75 filling level. Based on the simulation results, it can be concluded that the intensity of sloshing pressure, velocity, and force in the spherical tank can be reduced by introducing curved baffle with appropriate geometry. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.