An electrolytic perovskite and method for synthesizing the electrolytic perovskite are described herein. Basically, the electrolytic perovskite is a solid that has an ion conductivity greater than 10−5 S/cm in a temperature range of 0–400° C., wherein the ion is Li+, H+, Cu+, Ag+, Na+ or Mg2+. For example, Li1/8Na3/8La1/4Zr1/4Nb3/4O3 (5.26×10−4 S/cm) and Li1/8K1/2La1/8NbO3 (2.86×10−3 S/cm) are two electrolytic perovskites that have been synthesized in accordance with the present invention that have a high Li+ conductivity at 20° C. Both compositions have been confirmed in experiments to conduct Ag+ and H+ ions, as well. The present invention also includes a solid proton conductor that can be formed from the electrolytic perovskite by replacing the ions located therein with protons. The electrolytic perovskite and solid proton conductor can be used in a wide variety of applications or devices including, for example, a fuel cell, a membrane reactor, an amperometric hydrocarbon sensor or a steam electrolysis application.