MultiBiorefinery aims at fostering Portuguese bio-based economy by bringing value to forestry, agro-food, and fisheries wastes and by-products. This is a multidisciplinary scientific research and / technological development proposal submitted by a consortium of six research units with complementary expertises to create synergies that capitalize and optimize existing means and resources and to generate critical mass that will accelerate the production of knowledge and solutions to societal challenges, mainly in food sectors ensuring environmentally friendly practices. It is our goal to develop and use multi-purpose strategies and sustainable innovative technologies, namely industrial biotechnology and green chemistry, for by-products valorization towards a truly integrated biorefinery dealing with multiple feedstocks. (…) MultiBiorefinery aims to contribute to stimulating some of the strategic axes of development embodied in the Portuguese Strategy for Smart Specialisation, notably the “Production Technologies and Process Industries” with particular emphasis on the “Green Chemistry” and “Industrial Biotechnology” subtopics. Also, its vision is aligned with the circular economy and industrial symbiosis concepts and the proposals of the resource-efficient Europe Flagship initiative under the Europe 2020 Strategy, supporting the shift towards a resource-efficient and low-carbon economy to achieve sustainable growth.