Many children suffer from maltreatment and show the aftermath of these experiences even in adulthood. Child maltreatment can lead to impaired sleep. This study examines pathways in which the association between child maltreatment and impaired sleep can be explained. In a cross-sectional questionnaire survey, maltreatment experiences (Childhood Trauma Questionnaire), romantic relationship satisfaction (Couple Satisfaction Index), attachment (Revised Adult Attachment Scale), cognitive hyperarousal (Emotion Control Questionnaire-rehearsal) and insomnia symptoms (Insomnia Severity Index) were assessed in 314 individuals aged 18-83 years and currently in a committed romantic relationship. Eligible participants (N = 57, aged 18-70 years) took part in an additional sleep assessment (actigraphy) and completed a questionnaire on sleep quality (Pittsburgh Sleep Quality Index). Demographic data were also assessed. Impaired subjective sleep was significantly predicted by child maltreatment experiences. In addition, rumination and romantic relationship satisfaction mediated the association between child maltreatment and adult sleep quality. A serial mediation from child maltreatment via comfort with closeness and romantic relationship satisfaction on sleep quality was found. Therapeutic treatments should focus more on sleep quality. Furthermore, they should also consider rumination to decrease the effect of child maltreatment on sleep quality. Sleep should also be taken into account in emotional regulation therapies for children as well as couples therapy in adulthood to decrease the effect of sleep impairments and child maltreatment on further life.© 2021 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.