Titanium dioxide (TiO ₂ ) nanoparticles (NPs) are one of the topmost widely used metallic oxide nanoparticles. Whether present in naked form or doped with metals or polymers, TiO ₂ NPs perform immensely important functions. However, the alteration in size and shape by doping results in improving the physical, chemical, and biological behaviour of TiO ₂ NPs. Hence, the differential effects of various TiO ₂ nanostructures including nanoflakes, nanoflowers, and nanotubes in various domains of biotechnology have been elucidated by researchers. Recently, the exponential growth of research activities regarding TiO ₂ NPs has been observed owing to their chemical stability, low toxicity, and multifaceted properties. Because of their enormous abundance, plants, humans, and environment are inevitably exposed to TiO ₂ NPs. These NPs play a significant role in improving agricultural attributes, removing environmental pollution, and upgrading the domain of nanomedicine. Therefore, the currently ongoing studies about the employment of TiO ₂ NPs in enhancement of different aspects of agriculture, environment, and medicine have been extensively discussed in this review.