Vibration-based energy harvesting using a disk-type piezoelectric bimorph with thickness poled circular piezoelectric laminates is explored theoretically and experimentally. The bimorph disk consists of two circular laminates electrically connected in series and shunted through the outer surface electrodes to an electrical load for characterizing the power output and piezoelectrically shunted vibration in response to base excitation. The bimorph disk with free edge conditions is mounted to the vibrating base from its center and the focus is placed on the fundamental axisymmetric vibration mode. Electromechanical coupling is introduced to the distributed-parameter model of the thin circular plate and a resistive load is considered across the electrodes. Following a modal analysis-based electroelastic solution, closed-form expressions are obtained for the voltage output and shunted vibration frequency response functions by accounting for the two-way coupling in the presence of a finite electrical load impedance. Experimental validations of the electroelastic model are given for two separate bimorph disks of different diameters.