This chapter focuses on empirical studies in which the participants are very young children and the outcome measure is word learning. It examines why it is important to study word learning through overhearing, and provides an overview of current findings before turning to directions for future research in the area. There are both theoretical and practical implications of children’s ability to learn through overhearing. From a very young age, children are very active participants in their own language development. Overhearing studies reflect the real-life contexts in which young children encounter and learn words. One criticism of the experimental studies of word learning through overhearing concerns the type of speech used in the third-party conversation. A major impetus for the early experimental studies of learning through overhearing came from observational studies demonstrating both inter- and intra-cultural differences in the extent to which young children monitor third-party interactions.