The ‘illusion of control’ is an influential psychological theory stating that people frequently overestimate the extent to which they can affect outcomes in objectively-chance based events. The illusion of control was first demonstrated in purely chance-based gambling games such as the lottery and craps, and has gone on to be particularly influential in gambling psychology, where it has been proposed as one of the core cognitive illusions underlying disordered gamblers’ irrational thoughts about gambling. This theory therefore also has important applied implications, as the correction of cognitive illusions forms the basis of current gold-standard CBT treatments for gambling disorder, for which the NHS is opening 15 new clinics. In this talk I will discuss research which aims to conceptually-replicate early gambling-based illusion of control effects, and conclude with various implications both for gambling psychology and the treatment of gambling disorder.