The importance of imagination in education has a significant history (Egan, 1986, 2001; Eisner, 1976; Greene, 1988; Steiner, 1954; Warnock, 1976); however, scholarship is often theoretical, and the involvement of imagination in understanding sustainability is often overlooked (Jones, 1995; Judson, 2010; Stewart, 2009). Imagination has rarely been the subject of Environmental Education (EE) and research. Its nature is contested, and its workings can be concealed by formal notions of knowing and learning. Contemporary environmental philosophies argue that education can often contradict its aims through limited understandings of environment and knowledge (Orr, 1991,1992; Weir, 2008; Whitehouse, 2011). This thesis reconceptualises imagination as a way of knowing and learning in environmental terms. The study investigates the role of imagination in Education for Sustainability (EfS) contexts and critically analyses how imagination is involved in understanding sustainability for teachers and learners. The possibility of imagination as environmental knowledge, and as essential to resolving environmental problems, is applied in this research.