Photo- and electro-induced catalysis offers nascent opportunities not only to shift conventional chemical methods to more sustainable ones by exploiting renewable energy to shorting synthetic routes but also to synthesize renewable fuels. This chapter introduces the primary catalytic examples mediated by well-defined manganese-based molecular catalysts that are electro- or photoinduced. The chapter expands through redox transformations of organic molecules (oxidations and reductions) as well as the use of manganese complexes as catalysts for CO ₂ reduction reactions mediated by photo- or electrochemical processes. The presented examples illustrate that manganese species can be efficiently utilized to develop challenging synthetic transformation employing photo- and electro-induced catalysis.