Algae-powered bioelectronics is a combination of biological metabolism and engineered interfaces that deliver renewable electric energy while remediating environmental pollutants at the same time. In this particular field, bio-photoelectrochemical cells (BPECs) exploit whole or subunits of micro- and macroalgae to capture sunlight and enhance the extracellular electron transfer. Cyanobacteria like Spirulina, Synechocystis, and other photosynthetic algae such as Chlorella use their natural photosynthetic systems that are in-built with light-harvesting systems in order to convert sunlight into electrical energy by transmitting electrons to electrodes. During this process, the algae utilize environmental carbon dioxide that indirectly helps in intrinsic carbon sequestration and also reduces the cost of CO2 supply. This concept is extended by photosynthetic microalgae–microbial fuel cells (PMMFCs) that pairs an anodic consortium of bacteria or similar systems with an algal cathode, thereby combining wastewater treatment with electricity generation. Selected targets and microalgae cultivation mitigate the characteristic sluggish oxygen-reduction reaction at the cathode, elevating power outputs and treatment efficiencies. Recent research studies have led to advancements in creating eco-friendly and highly conductive electrodes using biofilms. Using graphene and similar materials arranged in thin, organized layers using Langmuir–Blodgett method provides a large surface and good electrical flow, which helps produce more electricity. Complementary coating strategies such as dip, spin and spray coating, electrophoretic deposition and layer-by-layer assembly provide scalable routes to tailor film thickness, porosity, and functionality for diverse device architectures. Together, these innovations position algae-driven BPECs and PMMFCs at the nexus of green technology and biological innovation. By integrating carbon capture, pollutant removal, and clean electricity generation into a single platform. Algae-powered bioelectronics offer a viable, low-cost pathway toward climate-positive energy and water-treatment solutions and emphasize the potential of living systems when combined with advanced materials science.