Objective To evaluate the effect of mindfulness therapy on sleep problems in adolescents. Methods We searched PubMed, Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure, Wanfang, Chongqing VIP and SinoMed for relevant randomized controlled trials on mindfulness intervention to improve adolescents’ sleep. The retrieval time was from the establishment of the databases to October 21, 2022. The results were meta-analysed with RevMan 5.4 software. Results A total of 11 randomized controlled trials were included, with a total sample size of 870 cases. The types of mindfulness therapy include mindfulness-based stress reduction, mindfulness-based cognitive therapy, mindfulness meditation, group mindfulness sleep intervention, body scanning and other mindfulness technologies. The duration of single intervention was different. The included studies showed that the mindfulness intervention can effectively improve the sleep problems of adolescents and the accompanying daytime sleepiness, anxiety, depression and other negative emotions compared with the control intervention. Meta-analysis of six studies showed that the sleep quality of adolescents in the mindfulness intervention group was improved [mean difference=−1.21, 95% confidence interval (−1.58, −0.83), P<0.00001]. Conclusion Mindfulness therapy has a good effect on improving adolescents’ sleep problems, but whether it can achieve long-term benefits still needs to be further evaluated by high-quality, multicenter long-term follow-up trials.