Circular transition of waste is a systemic approach aimed at transforming waste materials into valuable resources, products, or energy through various processes such as recycling, upcycling, composting, product recovery, and all forms of waste-to-X (WTX) technologies. Among many WTX technologies, subcritical water (SCW) technology, also known as hydrothermal treatment stands out as it uses only water at high pressure and temperature conditions to break down all kinds of organic waste matter. This advanced technology highlights several added advantages such as the capability of short reaction time, environmentally friendly solvent i.e. water, no incineration, no emission of harmful gases, and provides complete disinfection of bad bacteria and viruses in the waste by sterilization, deodorization, detoxification, and decomposition. The output from the SCW process comprises of organic rich materials that can be formulated into various value-added products and at the same time enhance the nutritional quality of organic waste used through rapid hydrolysis. The use of SCW technology approach towards circular economy promotes a sustainable approach to solid waste management through waste + water = X.