Living organisms display an astonishing morphological and behavioral diversity shaped by extrinsic environmental conditions and by intrinsic changes in developmental processes. In turn, such developmental trajectories are contingent on a myriad of regulatory interactions occurring at all possible steps of gene expression and cellular function. We are pleased to present a Frontiers Research Topic composed of 10 original research articles and reviews whose focus, ideas, and hypotheses reflect the current diversity and future directions of the field of Evo-Devo.