Two-dimensional (2D) materials hold transformative potential for next-generation electronics. The integration of high dielectric constant (k) dielectrics onto 2D semiconductors, while maintaining their pristine properties by low-defect-density interfaces, has proven challenging and become one performance bottleneck of their practical implementation. Here, we report a wet-chemistry-based method to fabricate amorphous, transferable high-k (42.9) copper calcium titanate (CCTO) thin films as high-quality, dual-function dielectrics for 2D electronic devices. The chelation-based Pechini approach guarantees uniformity in this perovskite-type complex oxide, while the transferrable feature allows its harmless integration to 2D semiconductors interfacing with a nanogap. The CCTO-gated MoS