This chapter discusses the field of moral development and explores what this research field can tell us about virtue development, which is a relatively neglected topic in virtue theory. The chapter is primarily about moral development in children, both because there is substantial scientific interest in this population and because virtue development must begin in childhood. Moral development research illuminates three apparently naturally developing preconditions for virtue development: (1) the ability to choose, (2) an interest in collective welfare, and (3) an interest in ethical normativity. Moral development research is also compatible with the STRIVE-4 Model in that it is primarily quantitative. Moral development generally does not focus on traits, with the exception of some research on moral identity, moral emotions, and moral exemplars. The chapter concludes by exploring how virtue science can contribute to moral development research, including an increased emphasis on (1) person-centered research, (2) the contextualizing of development in situations and roles, (3) flourishing, and (4) practical wisdom.