Systems engineers have often paid too little attention to the nature of the so-called “users” of products under development. These are better called stakeholders, as many roles are involved, and few of those are in direct contact with the developed products. A simple and robust conceptual framework for classifying development stakeholders — a taxonomy — is proposed. The taxonomy is product centric, with concentric “circles” denoting broad categories of stakeholders. Within these, generic “slots” describe typical classes of stakeholders; these are subdivided into “roles,” which are expected to vary at least in name with the domain. Examples are given, and a popular template is reanalysed using the framework. The taxonomy has immediate value in identifying and validating stakeholder roles in requirements elicitation, helping to ensure that key viewpoints are not missed, and hence reducing the risk of instability and failure during development.