This chapter reviews previous studies on interpreter ethics in conference settings with focus on the five common and near-universal ethical principles, i.e. competence, integrity, confidentiality, fidelity, and neutrality, in particular, how they are codified by professional interpreter (and translator) organizations and how they are practised by interpreters in real life. Up-to-date examples cited from literature and real-life events and two reasons for interpreters to deviate from requirement of professional ethics are analyzed – different sets of ethical models (teleology vs. deontology) and interpreters’ dual/multiple identities. This chapter also points out the emerging ethical issues in conference interpreting, such as ethics education in conference interpreter training programs, ethical issues in machine/AI interpreting, collaboration of human interpreters and AI interpreters, and location of conference interpreters. Our research proceeds from a holistic perspective on conference interpreter ethics and generates an overall view. Hopefully it may shed some light on more in-depth and parsimonious study in the future.