Literacy plays a crucial role throughout the lives of all individuals and increasingly so for individuals with intellectual disabilities. Literacy adds signiﬁcantly to the quality of life of individuals with intellectual disabilities, both academically and emotionally (Erickson, 2005; Moni & Jobling, 2000, 2001). With a focus on living independently, literacy can contribute to the development of skills in problem solving, choice making, and communication, which are required for daily life in the community (Ashman & Suttie, 1995; Erickson, 2005; van den Bos, Nakken, Nicolay, & van Houten, 2007). Despite the obvious importance and advocacy for developing literacy skills for successful and rewarding participation in the community across the lifespan, limited research has been undertaken to investigate the literacy education of young adults and adults with intellectual disabilities. This chapter discusses the notion of “literate invisibility” (Kliewer, Biklen, & KasaHendrickson, 2006). The ﬁrst part of the chapter explores why, until recently, the literacy skills of young adults and adults with Down syndrome have appeared to be invisible to educators, the community, and researchers, suggesting some of the contexts and causes that have contributed to the neglect of the needs and aspirations of young adults and adults around literacy education. The second part of the chapter discusses recent research evidence for the continuing literacy development of young adults and adults with Down syndrome, focusing initially on research in teaching reading. In this section, the roles of oral language, digital literacies, and popular culture in literacy and literacy learning are discussed. The third part argues for the need for research that draws on socio-cultural theories of learning that embrace a broader understanding of literacy development and education to encompass wider educational and research contexts, build effective teaching strategies, and focus on the individual’s purposes for literacy. The fourth part presents a case for a lifelong learning perspective that provides support and on-going literacy education for young adults with intellectual disabilities, including Down syndrome. This leads into a ﬁnal section that considers implications for practice.