Architecture has an ancient relationship to mathematics, and symmetry—in the broad sense of the term—is a core topic of both. Yet the contemporary application of theories of symmetry to architecture and built environments is a surprisingly immature area of research. This paper surveys the literature across a range of fields, assessing current evidence for the impacts of symmetry in the built environment upon human perception and well-being. The conclusion proposes a new research agenda toward further development of this promising subject area.