Background: Sleep problems are common in children and are known to detrimentally affect language and cognitive abilities, as well as academic achievement. Aims: We aimed to investigate effects of sleep on oral word and non-word reading in a large, cross-sectional sample of children. Sample: Of 428 children who attended a public psychological science event, 339 children aged 4-14 years (mean 8;10 ± 2;2) took part. Methods: Parents completed two sleep questionnaires (Children's Sleep Habits Questionnaire and Sleep-Disordered Breathing Questionnaire) whilst children completed the Test of Word Reading Efficiency. Results: Hierarchical multiple linear regression assessed whether parentally reported sleep problems were able to predict word and non-word oral reading speeds as measures of sight word reading and phonemic decoding efficiency, respectively. Children with parent-reported increased sleep-disordered breathing, daytime sleepiness, and shorter sleep latency had poorer performance on the reading task for both words and non-words, as well as the total combined score. The models explained 6-7% of the variance in reading scores. Conclusions: This study illustrates associations between sleep and word and non-word reading. The small but significant effect is clinically meaningful, especially since adverse factors affecting children's reading ability are cumulative. Thus, for children with multiple risk factors for poor reading ability, sleep problems may be another avenue for treatment. Since reading ability is a strong predictor of later academic success and life outcomes, our study provides important evidence to suggest that children with sleep problems should also be screened for literacy difficulties, and children with literacy difficulties be screened for sleep problems.