A lot of efforts were put into the design of torque converter blade angles and the analysis of transient flow behaviors; yet little is known about the influence of the blade thickness distribution on the performance or structural response of a torque converter. This study proposed a parameterized blade thickness design model and analyzed the effects of the blade thickness on hydrodynamic performance and structural response using fluid-structure interaction (FSI) models. Both one-way FSI model and two-way FSI model were built and evaluated against test data, and it was found that the transient two-way FSI model outperformed the steady-state FSI model in terms of both flow and structure simulations. It was found that the stall torque ratio and peak efficiency exhibited positive correlations with blade thicknesses, whereas the stall capacity constant was inversely related to blade thicknesses. Both numerical and experimental results suggested that the pump-turbine interaction induced serious flow fluctuations, and FSI simulations were required in the design process to avoid potential resonance.