Tin oxideTin oxide (SnO2)-basedNanostructures nanostructuresSnO nanostructures have gained huge recognition as a promising material in energyEnergy harvestingEnergy harvesting and storage due to their unique chemical, opticalOptical, and electrical characteristics. This chapter discussed in depth the properties, synthesis, and their applicationsApplications as anode materials of the batteries, components of supercapacitors, and nanogenerators. In the field of batteries, SnO2 nanostructuresSnO nanostructures exhibitNanostructures significant potential as anode materials due to their high theoretical capacity, cycling stability, and electrical conductivity, and further contribute to the improved charge–discharge rate and extended batteryBattery life. For capacitors, the porous nature and high surface area of SnO2-basedNanostructures nanostructuresSnO nanostructures enhance the electrochemical activity and result in increased energyEnergy and power density. Their structural features help in efficient ion transport and storage, which makes them superior compared to conventional materials. Furthermore, their excellent chemical stability and high electron mobility help them to efficiently convert the mechanicalMechanical energyEnergy to electrical energyEnergy, thus proving to be quite promising in energyEnergy harvestingEnergy harvesting. This chapter also highlights the various challenges associated with the practical implementations of SnO2-basedNanostructures nanostructuresSnO nanostructures in energyEnergy storageEnergy storage devices. Overall, the SnO2-basedNanostructures nanostructuresSnO nanostructures have appeared as a versatile and effective solution for the next-generation energyEnergy harvestingEnergy harvesting and storage technologies and provide a pathway toward more efficient and sustainable energyEnergy systems.