This chapter engages with research in lingua franca scenarios, defining this term and arguing for the value of adopting a linguistic ethnographic approach in this area. The development of the field of English as a Lingua Franca (ELF) is outlined. Historical antecedents for lingua franca studies in interactional sociolinguistics are identified, including work on intercultural miscommunications, the study of English as an international language and the identification of pragmatic strategies in ELF scenarios such as the let-it-pass procedure. The chapter considers critical debates, including the need to challenge the norms of standard language pedagogies, and the importance of maintaining a critical perspective on the current global dominance of English. It provides a review of current areas of focus in this area, including studies of English as lingua franca in higher education in an increasingly internationalised university system, and in workplaces. The range of methods drawn on in ethnographic studies of lingua franca scenarios is described, and implications for practice are identified in relation to the teaching of English and language policy and planning. Directions for future research identified include the emergence of social and linguistic norms in interaction, and developing the focus on lingua francas other than English.