Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder, characterized by symptoms of inattention, hyperactivity and or impulsivity. First line treatment is medication; however, medication alone may not provide sufficient functional improvement for some patients, or be universally tolerated. A recent surge in research to treat ADHD using non-pharmacological interventions demands a comprehensive, systematic review of the literature. The aim of this review was to examine the evidence base for psychological treatments for ADHD management in adulthood. A systematic search of PsycINFO, MEDLINE, CINAHL, AMED, PubMed, and EMBASE was undertaken until January 2019 for peer-reviewed articles exploring psychological interventions for adults (18 years with no upper limit) diagnosed with ADHD. A total of 53 papers were identified for inclusion. Collectively, 92% of studies (employing various non-pharmacological interventions) found a variant of significant positive effect on either primary or secondary outcomes associated with ADHD. The strongest empirical support derived from Cognitive Behavioral Therapy interventions. In addition, findings indicated support for the effectiveness of Mindfulness, Dialectical Behavior Therapy and Neurofeedback. Other types of interventions also demonstrated effectiveness; however, support was limited due to lack of available research and methodological rigor. Psychological interventions should be considered a valid and useful addition to clinical practice. Implications and areas for future research are discussed.