OLEAF4VALUE is a three-year project that will develop a complete valorization system for the olive leaf. 4,5 million ton of olive leaves are produced annually in the world by the olive oil industry, a key industry in southern Europe and along the Mediterranean coast (Spain, Italy, Greece, Portugal, Slovenia, among others). This recalcitrant biomass represents a problem for both the farmers and the whole olive oil industry, who need to remove it from the fields and the olive oil mills. This biomass is nowadays burnt in the fields, given to the cattle or, in some cases, combusted to produce energy. OLEAF4VALUE will put together a competitive consortium of highly experienced partners devoted to the complete valorization of this new underexploited biomass. The consortium will address all the stages of the value chain: raw material, biorefining, post-extraction technologies, market validation and sustainability assessment. The goal of OLEAF4VALUE is to set up the basis of a smart value chain based on a newly developed 4.0 concept: Smart Dynamic Multi-Valorization-Route Biorefinery (SAMBIO) for the cascade valorization of the olive leaf biomass according to its physicochemical composition, particularly modulated by specific pretreatments to produce target products. Advanced green extraction and isolation technologies will be used to sequentially separate all fractions and compounds of value, with a zero-waste approach. Enzymatic biotransformation and nanoencapsulation technologies will be applied to develop tailor made prototypes according to end user market needs from high value sectors: food, feed, health, cosmetic, pharma and chemical industries. Large companies from these sectors within the consortium will guarantee a good market-oriented approach throughout the project. OLEAF4VALUE will link the primary olive sector from southern Europe with large multinationals from the high valued competitive markets in a circular bioeconomy project.