Abstract
This chapter explores the role of consent in health data and tissue research. While such research is often low risk and does not involve direct interaction with patients, it still raises ethical concerns due to participants' enduring connections to their data and tissue, risks of privacy breaches, and the potential for harm or misuse. The chapter reviews the history and current norms of research consent, describes the wide variety of data and tissue research, and considers when and why consent is necessary in data and tissue samples in research. It outlines a range of consent mechanisms - explicit, broad, dynamic, opt-out and waivers - and examines the ethical justifications for each. I argue that promoting public trust and social licence are especially important when research proceeds without patient consent. In these cases, community engagement and responsiveness to public expectations can help demonstrate respect, minimise harm and protect the legitimacy of research, particularly for underserved and marginalised communities.