SnO₂ nanocomposites and nanomaterials such as SnO₂ QDs have applications in various advanced catalytic technologies, sensors, energy production (such as solar cells and water splitting), as well as in energy storage, including lithium-ion batteries and supercapacitors and because of their distinct qualities and properties. The various synthesis methods will be covered in this review, including conventional processes such as hydrothermal, solvothermal, pulsed laser ablation decomposition, electron beam irradiation, microwave-assisted, and other synthesis approaches. The benefits and drawbacks of various synthesis processes, as well as workarounds, suggest further study. This literature also focuses on multiple applications, including Photocatalysis, Lithium-ion batteries, gas sensors and other domains. The methods for producing tin oxide nanoparticles using modified and unmodified SnO₂ QDs were also studied. Creating SnO₂-based nanocomposites will encourage the next generation of chemists to modify and produce stable nanoparticles and nanocomposites capable of addressing critical environmental challenges. Future insights on the study of tin oxide quantum dot synthesis and its diverse uses are provided as this review comes to a close.