Energy storage technologies are necessary to overcome the intermittency of renewable energy source and achieve the transition away from fossil fuels. Hydrogen as an energy storage platform can break the scaling relations that restricts batteries from being a viable grid-level energy storage method. Hydrogen electrolyzers and fuel cell devices are the framework in which hydrogen can be used as a more efficient and CO2-free method of energy storage. Lowering materials cost, improving stability, and increasing efficiency are major feats that must be achieved for energy storage and utilization devices like electrolyzers and fuel cells to be cost competitive with current battery technologies. One major impediment to high energy efficiency in electrolyzer and fuel cell devices are the slow kinetics of the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), respectively. The reactions are typically catalyzed using platinum group metal (PGM) catalysts, which are high cost and limited in natural abundance on earth. Working in alkaline media allows for the use of non-platinum group metal electrocatalysts, such as first row transition metal (TM) oxides, thus significantly reducing costs. Unlike PGM catalysts, colloidal synthetic methods towards nanocrystalline first-row TM oxides, specifically spinel oxides, are less well developed. In this work, I developed novel colloidal synthesis routes to a host of ternary, multi-metal, high entropy, and/or heterostructured spinel oxide nanocrystals and demonstrate their activity towards alkaline ORR and OER. I developed novel insight into the compositional control of spinel oxide formation identifying precursor decomposition kinetics as the dominant parameter. Furthermore, I propose the growth of multi-metal spinel oxide phases is enthalpically favorable within a certain range of ionic radii and entropy may not be the dominant driving force for multi-component phase formation, despite the system being nominally high entropy. Utilizing synthetic methodologies optimized during my PhD, I was able to achieve the synthesis of monodisperse core@shell spinel oxide nanostructures with controlled shell thickness and composition for alkaline ORR, achieving one of the highest half-wave potentials for the reaction for a non-PGM catalyst. I characterized these various spinel oxide nanocrystals and electrochemical composites using physical characterization techniques such as X-ray diffraction (XRD), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS) and electrochemical techniques like cyclic voltammetry (CV) and rotating disk electrode (RDE) voltammetry.