Food oil by-products generated during vegetable oil processing are increasingly recognized as valuable resources within sustainable food systems. This review aims to evaluate current trends and future perspectives in the valorization of food oil by-products, focusing on technological developments, functional applications, and circular economy integration. A systematic literature search covering the period 2010 – 2025 was conducted using Web of Science, ScienceDirect, PubMed, ResearchGate, and Google Scholar databases in accordance with PRISMA guidelines, and 40 studies were included. Findings indicate that oilseed meals, press cakes, deodorizer distillates, lecithin fractions, and refining residues contain proteins, phenolic compounds, dietary fiber, and bioactive lipids with potential applications in food, feed, cosmetics, pharmaceuticals, and bio-based materials. Emerging technologies such as green extraction, enzymatic processing, membrane separation, and extrusion enhance functional properties and product quality. However, limitations related to food safety assessment, contaminant risks, and regulatory uncertainties remain significant barriers. Future research should prioritize safety standardization, process optimization, and regulatory harmonization to support sustainable industrial utilization globally.