Despite the increasingly protracted nature of situations of forced displacement, development policy makers and practitioners have tended to overlook the longevity of displacement. Forced displacement has long been viewed primarily as an emergency humanitarian issue by providers of development co-operation and the focus of the international community has predominantly been on addressing the immediate protection and short-term humanitarian needs of forcibly displaced persons. However, with increasing levels of new and protracted displacement, and key commitments such as the 2030 Agenda, donors are looking at the role of development actors and financing in supporting sustainable and comprehensive solutions to forced displacement. This Guidance, therefore, provides a clear and practical introduction to the challenges faced in working in situations of forced displacement, and provides guidance to donor staff seeking to mainstream responses to forced displacement into development planning and co-operation. While recognising that donor policies and responses are constantly evolving, this guidance proposes that donors responding to these situations prioritise three broad areas of work, where they can best contribute to existing capacities at the national, regional and global levels. It also identifies twelve actions, grouped under four key principles, outlining what donors can do to reinforce the capacities of key actors to respond to refugees and Internally Displaced Persons at the national, regional and global levels, and to advance comprehensive solutions.