[en] The frequency alignment of resonators is essential for wireless power transfer (WPT) systems to achieve strongly coupled magnetic resonances. Here, we present a novel tunable superconducting resonator for WPT applications. The tunable resonator is composed of a high-temperature superconducting (HTS) coil and a variable HTS electrode capacitor bank based on two series YBa₂C₃O_7−x–SrTiO₃–YBa₂C₃O_7−x thin films. The HTS coil serves as a wireless transmitting tool for power delivery, while the HTS electrode capacitor bank provides a frequency-tuning element for the resonator. At 77 K, the HTS materials cause low loss and thus achieve a high quality factor, while the incipient ferroelectric SrTiO₃ substrate with HTS electrodes has a nonlinear capacitance dependence on the applied electric field with no hysteresis. A voltage supply applies a continuous DC bias to both capacitors synchronously via the coil, adjusting the total capacitance and thus the resonant frequency. Our results indicate that the tunable resonator can achieve a tuning range of 12% from 775 kHz, offering a frequency-tuning functionality to superconducting WPT technology. (letter)