One-third of food produced for human consumption is lost or wasted globally, which amounts to about 1.3 billion tons per year. Food loss and waste (FLW) causes serious social, economic, and environmental issues undermining our planet’s sustainability. Therefore actions aimed at FLW prevention and reduction must be urgently taken. The unsustainability of the current economic model, based on a linear system of production and consumption, has emerged above all in the food sector, where little is being done to upcycle residues generated along the supply chain. In this context the shift to a circular economy (CE) model applied to this sector has become urgent, to promote the transition to a more sustainable agro-food system, moving toward a zero-waste industry. Recently, scientific research is examining the adoption of CE models, thanks to the “Sustainable Development Goals” publication. In this chapter, a review of the literature focused on the CE approach along the whole food production chain was performed, highlighting its benefits, with the perspective of developing a closed-loop agri-food system. Finally, we look at the key role played by nonconventional membrane process technology that constitutes a promising tool for waste valorization through the recovery of high-added-value compounds.