This review aims to systematically summarize existing evidence to determine the effectiveness of cognitive-based interventions (CBIs) on psychological health and well-being among parents of children with developmental disabilities (DD). Six databases were searched to identify eligible randomized controlled trials (RCTs) from their inception to April 2023. The revised Cochrane Risk of Bias tool for RCTs was applied to assess the risk of bias and the certainty of evidence was evaluated using the Grading of Recommendation, Assessment, Development and Evaluation. Meta-analyses were conducted using a random-effects model. Twenty-five RCTs involving 1915 participants were identified. The results indicated that CBIs reduced parental stress levels (Hedges' g = - 0.69), depressive symptoms (g = - 0.95), anxiety levels (g = - 0.78), and parental distress (g = - 0.29), and improved parental well-being (g = 0.62) and parent-child relationships (g = 0.43) postintervention compared with the active/inactive control groups. Subgroup analysis of the effectiveness of interventions using mindfulness-based interventions and cognitive behavioural therapy showed positive effects. The favourable intervention duration and participant targets were also identified in this review. Furthermore, the effects of CBIs were impacted by the different types of DD among the children. This review highlighted the positive effects of CBIs on parental stress levels, depressive symptoms, anxiety levels, parental distress levels, parental well-being levels, and parent-child relationships. Future well-designed RCTs are needed to further investigate the effects of MBIs and CBT interventions on children with DD and their parents, as well as the factors and mechanisms of action affecting the efficacy of these interventions.