Lithium silicates and aluminosilicates exhibiting a variety of typical silicate structures have been synthesized, and their ionic conductivities measured over a wide range of temperature and frequency, using a‐c methods and blocking electrodes. The frequency dispersion of the conductance and capacitance has been analyzed, and an equivalent circuit containing temperature and frequency dependent components is proposed. Frequency independent bulk conductances and activation enthalpies have been extracted and these are discussed in terms of the structural properties of these materials. The importance of a careful analysis of the frequency dispersion is demonstrated.