Dissociative experiences include various experiences and behaviors that can cause people to feel disturbed and disconnected from reality. Individuals with dissociative experiences may exhibit various symptoms, particularly in their inner speech. The present study examined how we can predict dissociative experiences based on inner speech in nonclinical populations by mediating the role of sleep disturbance. In this cross-sectional study, data were collected from university students aged 18 to 40 years (N = 400). They were asked to complete online self-report questionnaires: Varieties of the Inner Speech Questionnaire, Dissociative Experiences Scale, and Pittsburgh Sleep Quality Index. Results showed that there was a relationship between dissociative experiences and sleep disturbance (r = 0.29, p < 0.001), dialogic inner speech (r = 0.39, p < 0.001), condensed inner speech (r = 0.31, p < 0.001), other people's inner speech (r = 0.46, p < 0.001), evaluative/motivational inner speech (r = 0.28, p < 0.001), and total inner speech score (r = 0.48, p < 0.001). Thus, the current study showed a significant relationship among inner speech, dissociative experiences, and sleep disturbances. Inner speech was found to predict dissociative experiences by mediating sleep disturbances in the nonclinical population. Individuals with strong dissociative experiences had high scores for inner speech and sleep disturbance. The present study highlights a new area of research and its relationship to inner speech and dissociation. Future studies could further explore this new area to validate the findings reported here and support the authors' theoretical interpretation.