Background: This review aimed to synthesise the literature about interventions for parents of adolescents with intellectual disability, including parental experience of receiving interventions and intervention effectiveness. Methods: Eligible interventions aimed to improve parenting skills and/or parent-adolescent relationships, adolescent behavioural/emotional problems and/or parent well-being. ASSIA, EMBASE, Medline, PsycINFO and Web of Science were last searched on 11 July 2024. The TIDieR checklist and the MMAT were used for quality appraisal. A narrative synthesis was conducted. (Pre-registration: PROSPERO CRD42022384409). Results: Twelve studies with 1041 families were included. Intervention descriptions were detailed; however, study quality was mixed. Nearly all studies reported the intervention was associated with positive effects on parenting, parent-adolescent relationships, adolescent behaviour/emotional problems or parent well-being. Three randomised controlled trials (RCTs) offer the strongest evidence but are limited in quality. All studies investigating parent experiences reported positive responses. Conclusions: High-quality studies (e.g., RCTs) are needed to enable conclusions about efficacy and effectiveness.