The integration of big data and artificial intelligence into modern systems has profoundly influenced societal structures causing significant ethical challenges. This paper investigates the role of professional oaths in mitigating these threats by focusing on Dutch data professionals. Through a two-phase research approach, we first identify the essential attributes of effective oaths and then examine the societal values threatened by data and AI. A literature review with focus group validation, informs the development of a data professional’s oath. The proposed oath integrates eight core values—dignity, interpersonal trust, justice, self-control, autonomy, reliability, responsibility, and trustworthiness—providing a framework to guide ethical decision-making.