The aim of this study was to assess the effect of cognitive behavioural therapy intervention on sleep and health improvement in patients with cardiometabolic syndrome and sleep problems. This study also aimed to assess the effect of different study designs to explain the overall intervention effect through subgroup analysis. Relevant randomized controlled trial studies were searched through six online databases. The PEDro scale was used to assess the quality of the included studies. The random effects model was used to assess the mean difference, effect size, and standard deviation of the outcome variables. The heterogeneity of the included studies was assessed using I2 and Q tests. Publication bias was assessed by the Egger test. Cognitive behavioural therapy intervention provided a significant effect in improving the Pittsburgh Sleep Quality Index, Insomnia Severity Index, total sleep time, sleep efficiency, depression, fatigue, and HbA1c. The effect of cognitive behavioural therapy is more significant when relaxation training and education components are included. Cognitive behavioural therapy is suitable for the treatment of sleep problems in patients with cardiometabolic syndrome. Cognitive behavioural therapy is also effective on depression and fatigue but has a limited effect on blood pressure and biomedical indicators related to cardiometabolic syndrome.