The lateral bearing behaviors of suction bucket foundations for offshore wind turbines are investigated by centrifuge modelling in this paper. The centrifuge tests were performed in lightly over-consolidated clay and heavily over-consolidated clay, and three bucket foundation models with aspect ratios of 0.38, 0.5, and 1.3 were tested. The tests were force-controlled, and both static loads and cyclic loads were applied. In static tests, ultimate bearing capacities of suction bucket foundations were extracted from load-displacement curves as the first method, and the results were reinforced by stiffness-displacement curves. The displacement rates were calculated to find critical bearing capacities and ultimate bearing capacities of the foundations as the second method. The cyclic tests include cyclic loads with uniform and increased amplitudes. The accumulated lateral displacements and secant stiffnesses were discussed, and their variations with cycle numbers were studied.