The interconnection between reading and writing is a topic of great significance. Reading and writing, both fundamental components of literacy, go hand in hand as communicative acts involving written texts. Both activities involve meaning-making and print-related processes. Meaning-making encompasses accessing, activating, and retrieving information from prior knowledge; constructing mental representations; and integrating information (Kintsch, 1988). Additionally, reading and writing require print-related processes, such as accessing and retrieving orthographic knowledge and connecting it to sounds and meaning (Adams, 1990; Harm & Seidenberg, 2004). Although reading and writing processes are not identical, they share commonalities and utilize similar resources and skills; therefore, reading and writing skills should be related. Understanding the connections between reading and writing can shed light on how these skills develop, how they influence each other, and how they can be effectively nurtured in educational settings. In this chapter, I delve into the intricate relations between reading and writing, examining theoretical frameworks, empirical evidence, and the implications for future work as well as teaching and learning. [This chapter was published in: "The Handbook of Writing Research, 3rd Edition," edited by C. MacArther, S. Graham, & J. Fitzgerald, Guilford Press, 2025, pp. 109-124.]