The strategic design(er) is a figure whose skills, methodologies and tools can play a key role in addressing sustainability issues if it is placed at the centre of the project. After reviewing the concepts of sustainability and its link with Design, this contribution presents an analysis of the definition of Strategic Design for Sustainability that will highlight the key capabilities that make the strategic designer suited for tackling such complex problems. This chapter shows the need to guide companies, institutions and communities through the sustainable transition using typical Design methods and tools. The strategic designer is positioned within this framework, assuming the focal role of transition projects, by designing a shared future, the steps necessary to achieve it, and developing the more tactical aspects such as products or services.