Solid polymer electrolytes (SPEs) with good room temperature ionic conductivity and a high shear modulus are needed for future energy storage devices. Extensive studies have been devoted to searching for SPE with these desired properties. In this review, we will discuss recent progresses on the correlation between nanoscale morphology and ion conductivity in SPEs. Specifically, we will focus on anisotropic ion transport in five different types of SPEs with distinct morphological controls: crystalline structure, block copolymers, mechanical stretching, hybrids/nanocomposites, and holographic polymerization.