Childhood Apraxia of Speech (CAS) is a developmental speech sound disorder (SSD) notable for its severity and persistence of speech difficulties. A debate has surfaced historically about the cause of the speech and language deficits observed in the disorder. As children with CAS often present with comorbid language problems (i.e., receptive and expressive), learning disabilities (i.e., reading and spelling), and fine and gross motor difficulties, any conceptualization of the disorder should include an accounting of the multiple domains affected. However, CAS has been primarily viewed as a motor-speech disorder affecting speech production with consequences for expressive language. While there is extensive research about the association between an early diagnosis of other idiopathic SSD and poorer literacy outcomes, there is limited research investigating this same association for CAS. Given the increased risk of reading disorder (RD) with other idiopathic SSD, a better understanding of this association for CAS is crucial for children with this diagnosis. This dissertation research investigated literacy and literacy-related skills in a group of children with an early diagnosis of CAS (n = 16), ranging in age from 8 to 14 years. Comparisons were made with a group of children in a similar age range with a diagnosis of reading disorder without any history of SSD (RD-no SSD, n = 16). Results suggest that many children with an early diagnosis of CAS share the same degree of difficulty with word-level decoding as those diagnosed with RD-no SSD. In contrast, the two groups' phonological processing abilities were significantly different. The CAS group scored below the normative mean for phonological awareness and phonological memory, and the RD-no SSD group obtained mean scores within the average range.Additionally, subgroups were identified within the CAS participant group by average and below-average word-level decoding fluency. Below-average decoding fluency was associated with persistent speech sound errors, and phonological awareness and phonological memory deficits. Overall, these findings suggest that individuals with an early diagnosis of CAS and individuals with RD-no SSD demonstrate similar impairments in reading skills. However, the endophenotypes that underlie these literacy difficulties may differ between the groups, requiring remediation tailored to meet specific needs. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]