Biosolar conversion harnesses the complementary advantages of photo(electro)catalysis and redox biocatalysis to synthesize fuels and high-value compounds under sunlight. By routing renewable energy inputs through photo(electro)catalytic interfaces to biocatalysts, nature-inspired biosolar systems achieve highly selective and low-carbon chemical synthesis. This integration transcends the intrinsic limits of purely (in)organic or biological catalysis, advancing the frontier of next-generation sustainable chemical synthesis. Here, we introduce a comprehensive conceptual framework for solar-driven biocatalytic devices by elucidating their core mechanisms and thermodynamic foundations across photocatalytic, photoelectrocatalytic, and photovoltaic-photoelectrocatalytic platforms. We further highlight breakthroughs in the design of photobiocatalytic materials and devices, contextualized within coenzyme/mediator recycling, direct electron transfer, and H2O2 generation. Finally, we outline future directions toward practical and sustainable biosolar catalysis.