This article explores the available research literature on language development and language interventions among deaf and hard of hearing (d/hh) children. This literature is divided into two broad categories: Research on natural languages (specifically American Sign Language and spoken English) and research on communication systems (specifically iterations of signed English and cued speech). These bodies of literature are summarized, with special attention paid to intervention research and research exploring the impacts of language skills on literacy development. Findings indicate that there is generally a stronger research base on natural languages as compared to communication systems, though more studies in both categories are necessary. Additionally, there are very few intervention studies and even fewer that aim to intervene upon language with the explicit goal of impacting literacy; therefore, there is little known about whether and how interventions that aim to support language development may have direct or indirect impacts on literacy within this population. Further research on this topic, as well as replication studies and research with larger sample sizes, is strongly recommended.