Professional Identity (PI) is a social- and self-perceptive construct that describes how people understand themselves as professionals. PI guides professional development by shaping professionalism, role assumptions, responsibilities, values, and behaviour; and is a critical factor in professional performance and wellbeing. As such, PI has significant implications for how we support engineering designers in professional development and direct their social- and self-understanding. However, no current research provides a complete picture of PI elements important for Designers’ Professional Identity (DPI). This study aims to review and synthesise PI elements, currently discussed separately in the design literature, in order to propose a holistic understanding of DPI. Based on an extensive literature review, we find that DPI consists of two distinct sets of elements: Personal Attributes (PA) and Design Skills (DS). We present these two sets of elements in terms of meaning, possible relations between them, and their influence on DPI development. In addition, we propose multiple directions for future research.