This chapter reviews linguistic ethnographic research on academic writing. It outlines areas which have historically influenced this approach, including the sociology of scientific knowledge, the ethnography of communication, the US new rhetoric tradition and the academic literacies approach. It describes the methods which have been used in studying academic writing from an ethnographic perspective, explaining the difficulties associated with participant-observation of dispersed writing practices and how these can be mitigated against, particularly using text analysis and talk around text to gain a better understanding of writers’ experiences and practices. Research on student writing is described which explores how students develop discipline-specific expertise, how they draw on and repurpose resources in their academic writing, risk-taking, disciplinary expectations and the use of different technologies. Research on the writing of professional academics is then reviewed, including work on the discursive and genre practices of scholarly and disciplinary writing, and studies of academic writing in relation to the broader working conditions of academic life. Implications for practice are drawn out for teaching and transformative pedagogic approaches. Future directions identified include attention to inequalities in access to resources, managerialist approaches in universities and how digital communications technologies continue to transform academic writing.