In this study, a numerical investigation of potential sites for tidal current energy extraction is performed in Southern China seas by using the 3D hydrodynamic model FVCOM. The accuracy of the numerical model is validated by using 15-day data from 95 tide stations and 12 current stations. This study identifies 13 potential sites from 6 regions of interest where strong currents and appropriate water depths are suitable for tidal energy development. The modeling results show that the Dongchong Channel of Sansha Bay contains the highest depth-averaged tidal power density, reaching nearly 5000 W/m2. Moreover, the quantitative analysis is performed for different Tidal Current Turbines (TCTs) at the potential sites, considering not only energy yield but also stability of power output. The results indicate that the NNU-300 kW turbine with a rated power of 300 kW and a rotor diameter of 17 m performs the best in most locations in relatively deep water, while the Nova’s M100-D turbine with a rated power of 100 kW and a rotor diameter of 8.5 m is the most appropriate device in relatively shallow water sites. In addition, for most selected types of TCTs, the site H11 near the Fujian coast is the most promising location for future tidal farm development.