Plastic is a material that is widely used in modern life due to its affordability, resilience, and adaptability. Nevertheless, a severe environmental issue has resulted from the yearly manufacturing of around 400 million tons of plastic and a meager 9% recycling rate. Around the world, a considerable quantity of plastic waste gets thrown away every year, contaminating the soil, water, and air along with generating a significant amount of waste in landfills. It is well known that plastic pollution in marine and coastal environments is a significant issue caused by humans. The growing amount of plastic pollution in aquatic environments has proven unprecedented and continuous due to anthropogenic causes, disrupting the ecosystem's structure, function, and ultimately its essential functions and values. Plastics may break down into micro- to nanoparticles, and the finer particles are more likely to travel via soil, water, and air. As a result, a variety of detrimental effects, including ingestion, entanglement, ulceration, decreased reproduction, and oxidative stress, affect both terrestrial and aquatic species. Reusing and upcycling waste materials to create fuels is a potential way to reduce the amount of garbage that would otherwise harm the environment and our reliance on fossil fuels. Conventional recycling methods for plastic trash either recover inefficient thermal energy or provide compounds with lesser value than the original plastic. Value-added products made from plastic trash may now be produced sustainably through upcycling or the valorisation strategy. Upcycling is a useful method of converting plastic waste into high-value products and has the potential to significantly lessen the negative environmental effects of plastic production and consumption. This study focuses, in particular, on the processes used to convert plastic trash into high-value products, such as pyrolysis, solvent extraction, hydrogenolysis, photo reforming, and biological upcycling.