Oxygen electrochemistry is vital to numerous future renewable energy technologies, such as fuel cells, metal-air batteries, and electrolyzers. Active electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are known, however they are typically expensive and based on rare materials such as Pt (for ORR) and Ir/IrOx (for OER). These benchmark catalysts also suffer from reaction poisoning and poor electrochemical selectivity, further decreasing their utility. Therefore, catalyst materials that are highly active, stable, and cost-effective are needed. Manganese oxides (MnOx) are an attractive class of electrocatalysts due to their natural abundance, low cost and relatively benign nature. The ability to tailor the size, morphology, stoichiometry, crystalline phase along with the fact that manganese can exist in numerous valences (+2, +3, +4, +6, and +7) provides a real opportunity to drastically improve MnOx mediated oxygen electrocatalysis. The development of several MnOx and MnOx hybrid nanoscale electrocatalysts with properties rivaling that of the commercial Pt/C benchmark will be presented.   This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. Financial support was also provided by the Office of Electricity, Delivery and Energy Reliability.