In the last 20 years, ecocriticism has developed from its early incarnation as the relatively under-theorised preserve of nature writing enthusiasts to its current vibrant state as a sophisticated array of ‘earth-centred’ approaches to cultural criticism that mobilise and reframe theories drawn from a range of disciplines in- cluding ecology, philosophy, sociology and biology. Ecocriticism’s diversity also extends to engaging with a variety of literary forms as well as, increasingly, film, TV, digital environments and music, and to an interest in representations of the urban. At its heart is the conviction both that we are living in a time of ecological crisis that requires us to reassess with some urgency our modes of being in the world and that our cultural perceptions of ‘nature’ and the ‘human’, and the relationship between the two, have to a large degree been responsible for these damaging modes of being. Its role is to interrogate and critique these perceptions, even within environmentalism itself, with some ecocritics also committed to exploring alternative ways of conceptualising our relationship with the non-human world. This paper briefly traces the history of ecocriticism, discussing its initial development in the USA and Britain, outlining the two strands of social ecology and deep ecology that underpin its ongoing formulation, and tracing the ‘waves’ of its development. It then focuses on contemporary and emergent theorisations, in particular the global inflection of current post-colonial ecocriticism and the environmental justice movement, which introduces the new paradigm of eco-cosmopolitics, and the recent formulation of ecocritical post- humanism. This emphasises the imbrication of the human in earth’s matrix, drawing on the insights of ecofeminism, phenomenology and biosemiotics, and has its most recent incarnation in the currently emerging field of material ecocriticism, which, in its engagement with the complex entanglement of the human and the non-human, the social and the scientific, hints at a more dissonant paradigm.