In this work, we investigate the solvation of tetravalent thorium Th(IV) in aqueous solution using classical molecular dynamics simulations at the 10 ns scale and based on polarizable force-field approaches, which treat explicitly the covalent character of the metal-water interaction (and its inherent cooperative character). We have carried out a thorough analysis of the accuracy of the ab initio data that we used to adjust the force-field parameters. In particular, we show that large atomic basis sets combined with wave function-based methods (such as the MP2 level) have to be preferred to density functional theory when investigating Th(IV)/water aggregates in gas phase. The information extracted from trajectories in solution shows a well-structured Th(IV) first hydration shell formed of 8.25 ± 0.2 water molecules and located at about 2.45 ± 0.02 Å and a second shell of 17.5 ± 0.5 water molecules at about 4.75 Å. Concerning the first hydration sphere, our results correspond to the lower bounds of experimental estimates (which range from 8 to 12.7); however, they are in very good agreement with the average of existing experimental data, 2.45 ± 0.02 Å. All our results demonstrate the predictable character of the proposed approach, as well as the need of accounting explicitly for the cooperative character of charge-transfer phenomena affecting the Th(IV)/water interaction to build up reliable and accurate force-field approaches devoted to such studies.