Objective Telepsychiatry involves use of telecommunications technology to deliver psychiatric care and offers promise to reduce costs and increase access to mental health services. This systematic review examined cost reporting of telepsychiatry programmes for mental healthcare. Methods We systematically searched electronic databases for studies reporting costs, including economic evaluations such as cost-effectiveness analyses, or costs of developing telepsychiatry programmes for clinical care of mental disorders. Included studies enrolled participants with mental disorders and involved telepsychiatry for depression, anxiety disorders, serious mental illnesses including schizophrenia spectrum disorders and bipolar disorder, post-traumatic stress disorder, dementia or epilepsy. Results Twenty-six unique studies met inclusion criteria (17,967 participants), with most targeting depression (n = 7; 27%), general mental disorders and screening (n = 7; 27%), child mental health (n = 4; 15%) and geriatric mental health (n = 4; 15%). Nearly all studies (n = 25; 96%) compared telepsychiatry programme costs with either standard in-person consultation or usual care, with 15 (60%) reporting that telepsychiatry programmes were less expensive, and 8 (32%) showing telepsychiatry programmes were more expensive. Three studies reported cost-effectiveness analyses, favouring telepsychiatry programmes, but at highly elevated cost-effectiveness thresholds. Few studies reported costs of developing or delivering telepsychiatry programmes. Conclusion Costs of telepsychiatry programmes varied widely, with substantial heterogeneity in how costs were defined and reported. Some programmes cost less than in-person services while others cost more. Therefore, rigorous cost-effectiveness studies following established standards in economic evaluation are needed to inform implementation and sustainability of these programmes in health systems.