This study highlights the innovative use of increased rare earth elements to enhance the dielectric properties of materials and devices. The AlOC-129Ln series, features the highest number of rare earth dopants in aluminum oxo clusters to date. The trivalent ions in AlOC-129Ln impart a high dipole moment, significantly elevating the dielectric constant (k) of the doped polymer films. AlOC-129Ce, in particular, exhibits the largest molecular size, which enhances interfacial effects and achieves a relative dielectric constant four times greater than that of undoped polymers and 1.5 times higher than those with single rare earth dopants. The substantial molecular size (~2.5 nm) and robust charge scattering and trapping capabilities of AlOC-129Ln reduce dielectric loss by up to 50% at high frequencies. Additionally, its excellent solution processability enhances breakdown strength by 147%, ensuring superior electrical stability. This research demonstrates the versatility of the cluster doping strategy in effectively balancing dielectric constant and loss, unveiling the promising potential of solution-processable cluster materials in electronic devices.