High resolution characterization of materials for solid oxide fuel cells (SOFCs) have drawn attention in recent years due in part by advances made in instrumentation that enable in situ characterization during device operation. Transmission electron microscopy (TEM) and advanced techniques such as energy dispersive X-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS) have been widely used to characterize SOFC electrolytes, e.g. doped zirconia and doped ceria, in nanometer to atomic scale resolution. TEM and associated diffraction patterns enable the high resolution analysis of crystal structure of electrolyte at the nanoscale, while EDS and EELS are utilized to characterize their chemical composition in sub-nanometer scale. This paper reviews the use of these techniques for SOFC electrolyte characterization and presents new possibilities for SOFC materials research enabled by the introduction of recently developed technologies such as aberration-corrected or environmental TEM.