Tuned liquid dampers (TLDs) are passive control devices which are mainly used in tall structures and high-rise buildings to mitigate the unwanted vibration. A tuned liquid damper usually comprises of a rigid tank containing a shallow fluid. These are basically dynamic vibration absorbers which are used to control unwanted vibrations in structures subjected to various dynamic excitations. Fluid oscillating inside a tank is termed as sloshing and is responsible for the loss of energy of the host structure. Modelling and designing of a TLD is therefore necessary before its implementation to a host structure. This can be done either by numerical simulations or physical experiments. However, performing full-scale experiments is costly and time consuming. Taking this into account, various analytical and numerical models have been proposed by the researchers for the modelling of a TLD. However, the analytical models (e.g. equivalent mechanical model) are unable to capture the sloshing dynamics properly. Therefore, in the present research work, a numerical model of a TLD is developed following the computational fluid dynamics (CFD) approach. Both the two-dimensional and three-dimensional model of a TLD is developed in COMSOL Multiphysics (ver. 5.6) software to address the sloshing phenomenon. The results obtained from the numerical simulations for both these models (2D and 3D) considering free surface elevations and base shear forces are compared and are discussed.