This review discusses the research evidence for psychological treatment of gambling disorder. Several treatment options for gamblers have been explored, ranging from self-help and peer support, to brief and motivational interventions, to more intensive therapy approaches. Involvement in peer support programs seems to be optimal when combined with professional treatment; however, engagement and retention in peer support is limited. Self-directed interventions appear to benefit some gamblers; however, the involvement of therapist support, either in person or by telephone, may bolster these effects and such support need not be extensive. These self-directed options reduce the barriers associated with treatment-seeking, and may reach a wider range of gamblers than professionally delivered treatments alone. Brief and motivational approaches similarly may extend treatment options to more gamblers, namely at-risk and problem gamblers and those not seeking treatment. Of more extensive therapies, no consistent benefit of one approach emerges, although cognitive-behavioral interventions have been most often applied. Overall, several treatments have been developed for gambling disorder and results are promising, but variability in findings suggests a need for further systematic evaluation.