<p>This systematic review aimed to investigate (a) the core characteristics of reading ability in children with comorbid Developmental Dyslexia (DD) and Developmental Language Disorder (DLD), (b) the shared and distinct features of reading performance among children with DD, DLD, and comorbid DD + DLD, and (c) the linguistic and cognitive factors associated with their reading outcomes. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) guidelines, systematic searches were conducted in Web of Science, Scopus, and PubMed between January and May 2025, and a total of 18 empirical studies (published between 2000 and 2023) met the inclusion criteria. Overall, the included studies were conducted across four languages, comprising 15 cross-sectional studies and three longitudinal cohort studies. Risk of bias was assessed using the critical appraisal tools developed by the Joanna Briggs Institute (JBI). Children with comorbid DD and DLD exhibited the most severe and persistent reading difficulties across decoding, fluency, and comprehension tasks, reflecting an additive burden of phonological and language deficits. Comparisons across groups showed that DD primarily affected decoding, DLD impacted comprehension, and the comorbid profile encompassed both types of deficits. Key predictors of poor reading performance were phonological awareness, rapid automatized naming (RAN), semantic knowledge, and syntactic processing. In conclusion, children with comorbid DD and DLD present a qualitatively distinct reading profile that current diagnostic systems may fail to capture, and early identification as well as interventions targeting core language skills, particularly phonological abilities, are essential, while future research should prioritize longitudinal designs, cross-linguistic validation, and diagnostic tools that account for comorbidity.</p>