Freshwater ecosystems are in major decline at the global scale and there is an urgent need for successful restoration projects. Although freshwater restoration is a relatively new science, it is at the point where important principles and approaches that underlie success can be broadly established. Covering the full spectrum of freshwater habitats, including rivers, lakes, ponds, and various wetland types, this chapter sets out and discusses six key restoration principles concerned with project targets, diagnosing and tackling underlying and restraining influences, natural recovery and landscape-scale processes, as well as monitoring and working with stakeholders.