Building on the success of the 2016 conference held at Grand Hotel San Michele Cetraro, Italy, and that of the 2018 conference held at Comwell Borupgaard, Denmark; this third iteration of the conference will bring together a wide range of delegates from different scientific areas thereby taking a multi-disciplinary approach to assessment of waste and residual resources management in the framework of future sustainable economy. The economic growth, urbanization and increase in population have driven a huge increase in resource consumption, with the consequent release of large amounts of waste to the environment. Waste streams can be potential sources for new products, and can improve the efficiency of resource utilization in a circular economy perspective. As a result, waste management and resource optimization are closely connected to each other. Traditional waste management options are often discussed as standalone technologies for specific waste flows, e.g., anaerobic digestion, thermal conversion, recycling, etc. Most current waste and resource management schemes lack a holistic approach, able to cover all the sustainability aspects of the whole chain from product design, raw material extraction, production and consumption of goods and services, re-manufacturing and re-use, resource recovery from waste down to its safe final disposal. Moreover, future solutions must be well integrated with other sectors in society, such as energy, transport, materials, chemistry, medicine, and more. In this framework, it is crucial to have reliable assessment methods, able to provide accurate and quantitative assessment of possible options for a more efficient utilization of resources and sustainable management of wastes. WasteLCA_3 conference addresses the latest developments in the area, focusing on methodologies and tools, such as Life Cycle Assessment, Life Cycle Costing and Social Life Cycle Assessment, which allow a fair and reliable comparison between the performances of different waste and residual resource management solutions. Methodological developments related to these approaches will be taken into account together with important case studies. The program includes keynote speakers, thematic sessions, workshops, and poster sessions. The intention is to stimulate fruitful discussions on innovative ideas and directions to be pursued in future research activities, as well as how these approaches can be transferred to practical application in society.