The biocompatibility, biodegradability, and non-toxicity of starch nanoparticles (SNPs) have made them an adaptable and sustainable material with a wide range of uses across many industries. The synthesis, characterisation, and possible applications of SNPs are covered in detail in this article. Numerous techniques, including as enzymatic hydrolysis, high-pressure homogenization, and nanoprecipitation, can be used to synthesize SNPs; each has unique benefits and drawbacks. Determining the size, shape, and surface characteristics of SNPs requires the use of characterization techniques such dynamic light scattering (DLS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Exploration of SNPs in several domains has been prompted by their unique features. SNPs improve the bioavailability and regulated release of medications in drug delivery devices. They extend the shelf life and texture of items in the food sector. SNPs have potential for use in environmentally friendly applications including water filtration and biodegradable packaging. Their potential to increase crop output and sustainability is highlighted by their use in agriculture as pesticide and fertilizer carriers.