In this chapter, we explore the ethical considerations attending to research and practice in corpus linguistics. Despite the ubiquity of ethical dilemmas in corpus construction and use, there has been scant literature dedicated to ethical practices within the discipline. This gap is particularly pronounced given the increasing engagement with digital and online data sources, which pose unique ethical challenges regarding issues such as consent, privacy, and the public-private dichotomy. The chapter addresses these ethical considerations, and more besides, from the inter-related perspectives of research participants, corpus builders, distributors, and users. Importantly, the chapter highlights how ethical considerations are not confined to discrete stages of corpus linguistic projects but, rather, are interwoven throughout the research lifecycle. Key issues addressed include informed consent, participant anonymity, the ethical implications of using publicly available versus private communications, and the responsibilities of corpus users to ensure the meaningful, truthful, and fair representation of their findings. The chapter aims to respond to the need for more nuanced ethical guidelines that reflect the diversity of data sources and research contexts that characterise contemporary corpus linguistics, advocating for a reflective, case-by-case approach to ethical decision-making.