This chapter examines the theoretical and empirical foundations of the roles of morphological and semantic skills in developmental dyslexia. Morphemes are the minimal units of meaning by which we create new words in any given language (e.g., “magic”+“ian” = “magician”). Semantics is the study of meaning, broadly speaking. In this chapter, we review data on children’s access to meaning at the word and sentence level in tasks, primarily in the oral modality. This review is important because of two common assumptions. The first is of the dominant role of phonological skills in dyslexia, an assumption that has limited the scope of empirical exploration into other potentially implicated factors. The second is that people with dyslexia have a strength in morphology and semantics, a speculation with surprisingly little empirical foundation. We first review the theoretical background for these speculations. We then present the available research evidence, focusing specifically on children with dyslexia, for alphabetic, morphosyllabic, and abjad writing systems.