Sustainable development, a foundation of the post-2015 global agenda, depends on healthy and productive citizens. The origins of adult health begin early in life, stemming from genetic–environmental interactions that include adequate nutrition and opportunities for responsive learning. Inequities associated with inadequate nutrition and early learning opportunities can undermine children’s health and development, thereby compromising their productivity and societal contributions. Transactional theory serves as a useful framework for examining the associations that link early child development and nutrition because it emphasizes the interplay that occurs between children and the environment, mediated through caregiver interactions. Although single interventions targeting early child development or nutrition can be effective, there is limited evidence on the development, implementation, evaluation, and scaling up of integrated interventions. This manuscript introduces a special edition of papers on six topics central to integrated child development/nutrition interventions: (1) review of integrated interventions; (2) methods and topics in designing integrated interventions; (3) economic considerations related to integrated interventions; (4) capacity-building considerations; (5) examples of integrated interventions; and (6) policy implications of integrated interventions. Ensuring the health and development of infants and young children through integrated child development/nutrition interventions promotes equity, a critical component of sustainable development.