Agro-waste valorisation is emerging as a high-value strategy to reduce agricultural residues while replacing fossil-based plastics and synthetic agrochemicals. Converting crop residues into bioplastics and plant bio-stimulants aligns with circular economy goals by closing material loops and reducing waste. This article summarizes life cycle assessment (LCA) findings on these pathways, highlighting environmental benefits, key trade-offs, and design considerations for integrated biorefineries. Overall, agro-waste-derived products offer significant potential for lowering greenhouse gas emissions and resource use, though results depend strongly on system boundaries, energy supply, and allocation methods.