Product owners play a crucial role in the agile software development process, as they represent the interface between customers, stakeholders and development teams. In the literature, the role is sometimes defined by guides and frameworks; in research and practice, however, there are ambiguities and false expectations when it comes to the specific characteristics of the product owner role and the associated areas of responsibility. In order to close this research gap and to understand and structure the variety of product owner roles encountered in practice, findings from theory and practice were brought together and evaluated. Based on the extended taxonomy design process (ETDP) method, a product owner taxonomy including archetypes was developed. As part of the taxonomy development, three iterations were undertaken, incorporating two literature searches and seven expert interviews. The taxonomy was also empirically evaluated. The final taxonomy comprises six archetypes, four dimensions, 21 sub-dimensions, and three characteristics.