The collection of articles on the theme Evolution and Development of Neural Circuits explores how brains are built, diversified, and adapted in a variety of species, integrating perspectives from evolutionary biology, developmental neuroscience, and systems neurobiology. Recent advances in molecular genetics, neuroanatomy, physiology, imaging, and computational modeling have enabled unprecedented insights into the mechanisms that shape neural circuits. This collection brings together contributions from leading investigators who examine the architecture and function of neural circuits from multiple angles. Key themes include the evolutionary divergence and convergence of circuit motifs, the conserved molecular and developmental building blocks that underlie connectivity, and the selective pressures that sculpt neural systems to support behavior and cognition. Articles cover topics ranging from retinal mapping and interneuron diversity to thalamocortical connectivity, prefrontal circuit maturation, and the computational modeling of both normal and abnormal circuit development. Collectively, these essays reveal how molecular signaling, cellular variability, and theoretical principles converge to shape the formation and function of circuits across vertebrate and invertebrate brains.