A growing body of research has focused on the role of play in young children's literacy development and early-literacy learning. In reviewing this research, the authors define the play-literacy nexus as that space where play, language, and emerging literacy behaviors converge and interact. They describe findings about the play-literacy nexus (which they call knowledge "of" the nexus) and what these findings mean for children, their parents, and their teachers in literacy development and early-literacy learning (which they dub knowledge "in" the nexus). They define play and literacy in terms of this current knowledge; they review the major theoretical frameworks that give rise to play-literacy hypotheses and relationships; and they discuss topics that connect play and literacy, including literacy-enriched play environments, play's role in narrative development, and how play supports cognitive-linguistic abilities and skills that help children learn to read. They argue that knowledge of the play-literacy nexus, i.e. research, should determine the nature of the knowledge used in the play-literacy nexus within the larger context of early-childhood education, and they illustrate their argument with several evidence-based techniques for classroom practice, including literacy-enriched play environment design, topic- and theme-related dramatic play, and play planning. (Contains 3 figures.)