BackgroundChronic diseases have a high prevalence worldwide, and patients with chronic diseases often suffer from depression, leading to a poor prognosis and a low quality of life. Metacognitive therapy is a transdiagnostic psychotherapy intervention focused on thinking patterns, with the advantages of reliable implementation effect, short intervention period and low cost. It can help patients change negative metacognition, alleviate depression symptoms, and has a higher implementation value compared with other cognitive interventions. Therefore, metacognitive therapy may be an effective way to improve the mental health of patients with chronic diseases.Methods and analysisCNKI, Wanfang Database, VIP Database for Chinese Technical Periodicals, Sinomed, PubMed, SCOPUS, Embase, The Cochrane Library, Web of Science and PsycINFO will be used to select the eligible studies. As a supplement, websites (eg, the Chinese Clinical Registry, ClinicalTrials.gov) will be searched and grey literature will be included. The heterogeneity and methodological quality of the eligible studies will be independently screened and extracted by two experienced reviewers. All the data synthesis and analysis (drawing forest plots, subgroup analysis and sensitive analysis) will be conducted using RevMan 5.4.1.Ethics and disseminationThis article is a literature review that does not include patients’ identifiable information. Therefore, ethical approval is not required in this protocol. The findings of this systematic review and meta-analysis will be published in a peer-reviewed journal as well as presentations at relevant conferences.PROSPERO registration numberCRD42023411105.