There are a variety of motives for participation in sports. Dating back at least to the Olympic games of ancient Greece, one such motive has been the development of character. The idea that sport can function as a builder of character was so popular that it eventually gained a place within our folk wisdom, as is reflected by the cultural adage "sport builds character." Only recently, however, has the truth of this claim been subjected to empirical investigation. In this chapter, we examine one aspect of the complex concept of character, namely, moral development, as it relates to sport. Moral development is not the totality of what is meant by character, anymore than knowledge exhausts what is meant by wisdom, but it is an important part. Moral development refers to the evolving maturity of a person's grasp of the interpersonal rights and responsibilities that characterize human social life.