The amount of waste produced by the agricultural and agro-industrial sectors is a global concern. What constitutes agro-industrial wastes? What are their disposal routes, and how can industries reuse them? While disposal methods may vary, these wastes are often improperly managed, causing significant environmental harm. However, there is considerable potential to repurpose this waste, transforming it into new products, including pharmaceuticals, thus reducing waste. This chapter presents a comprehensive overview of the different types of waste generated by the agricultural and agro-industrial sectors. It highlights the variety of raw materials available and how they can be repurposed to develop new medicines. We explore the potential of agro-industrial waste as a valuable resource in the transition to a circular economy. These sectors produce substantial waste, which, if not appropriately managed, can have negative environmental, public health, and socioeconomic impacts. Traditional linear economy models have treated these materials as residues; however, recent research shows their potential for transforming into high-value products like bioactive compounds, pharmaceuticals, biofuels, and bioplastics. The chapter discusses various technological approaches for processing and valorizing these residues, including pyrolysis, gasification, and biotechnological methods. These processes not only minimize waste accumulation but also facilitate the extraction of valuable bioactive compounds, supporting a more sustainable and economically viable industry. Aligned with the United Nations Sustainable Development Goals (SDGs), this chapter emphasizes integrating waste valorization strategies into agro-industrial practices to promote environmental responsibility and resource efficiency. It also highlights the importance of policy support, technological innovation, and collaboration between industries and governments to implement effective, sustainable waste management solutions.