Controversial therapies (CTs) are psychotherapies that lack an evidence basis, are implausible with respect to current psychological science, and may be associated with adverse events. CTs are rarely independently evaluated or transparently reported, and are often commercialized. Among CTs are Dianetics, primal therapy, transactional analysis, neuro‐linguistic programming, thought field therapy, recovered memory therapy, and attachment therapy. CTs have historical commonalities and share emphases on unconscious motivation, mind–body interactions, and views of memory that contradict established evidence.