This paper reports a strategy for controlling surface chemistry of barium titanate (BaTiO3) using surface-initiated reversible addition鈥揻ragmentation chain transfer (RAFT) polymerization of an oligothiophene monomer. The modular chemistry on the engineering of nanoparticles provides a facile pathway to compatibilizing dielectric nanofillers in a matrix of oligothiophene polymers, leading to the formation of nanodielectric composites with permittivity at 鈭?0 and dielectric loss <0.02 over a wide range of frequencies (1 kHz to 1 MHz). This approach could be generalized to a variety of nanoparticles with tunable dipolar polymer shells for the development of novel dielectric nanocomposite systems for energy storage.