Solution-state photocatalysis is an established and widely used synthetic methodology, employing visible light to drive energy and electron transfer reactions. In particular, metallaphotoredox catalysis, involving the synergistic dual use of a transition metal catalyst and a photocatalyst, has dramatically expanded the utility of light-driven transformations, and is one of the most valuable applications of photocatalysis towards the synthesis of industrially relevant small molecules. While copper and palladium complexes have seen some use in metallaphotoredox reactions, nickel complexes remain the cornerstone of these approaches, enabling a diverse range of new cross-coupling strategies. The key value of this approach stems from its complementary reactivity to traditional palladium-catalyzed cross-coupling reactions: palladium catalysis excels in the construction of C(sp2)-C(sp2) bonds, while photocatalyst/nickel-mediated C(sp3)-C(sp2) and C(sp3)-C(sp3) cross-couplings allow access to saturated substructures using a wider diversity of coupling partners. Within these reactions, typically the nickel catalyst undergoes oxidative insertion into an aryl or alkyl halide bond, traps radicals generated by the photocatalyst, and ultimately undergoes reductive elimination to afford the cross-couped product, while the photocatalyst is primarily responsible for generating radical species and for turning over the nickel cycle by modulating the oxidation state of the nickel catalyst via photoinduced electron transfer (PET), or by sensitizing the nickel catalyst via photoinduced energy transfer (PEnT), Figure . A wide range of oxidizable carbon-centered radical precursors are available; including carboxylic acids (following deprotonation), trifluoroborate salts, amines (as Katritzky salts), Hantzsch ester derivatives, and alcohols (primed as oxalates or NHC derivatives). Alkyl halides and alkanes can also be used as carbon-centered radical precursors by using an additional halogen atom transfer (XAT) or hydrogen atom transfer (HAT) agent, in selective reactions governed by the relative bond dissociation energies of the abstractant and substrate. Metallaphotoredox can also mediate carbon-heteroatom bond formations; including amination, etherification, thioetherification, esterification, and sulfonylation strategies, amongst others. The use of ancillary ligands (frequently 2,2'-bipyridine derivatives) or additives such as 1,4-diazabicyclo[2.2.2]octane (DABCO), 1,1,3,3-tetramethylguanidine (TMG) or tert-butylamine, are often required to promote reactions. Despite the versatility of metallaphotoredox catalysis, this approach has mostly been applied under strictly anaerobic, homogeneous catalysis conditions, requiring the use of toxic, unsustainable, and particularly flammable organic solvents such as N,N-dimethylacetamide (DMA), N,N-dimethylformamide (DMF), acetonitrile (MeCN), dioxane, or dimethylsulfoxide (DMSO). Their use at scale presents a combination of safety and sustainability concerns for industry, ultimately limiting the impact and utility of metallaphotoredox catalysis in industry.