This chapter focuses on the OHS professional as an ethical professional and foregrounds the complexity of ethics in OHS professional practice. It considers ethics in the context of the legal obligations of the OHS professional, introduces the concept of the OHS professional as ‘moral agent,’ and discusses ethical theory from a moral philosophy perspective as a basis for examining the role of formal codes of ethics and particular ethical challenges for OHS professionals. This is followed by discussion of individual and organisational ethical capability and practical approaches to ethical OHS decision-making, including consideration of ‘speaking up’ when the need arises. Appendices provide a summary of ethical theories and a compilation of OHS scenarios to prompt professional discourse.