Title Do non-clinical services help to improve functional outcomes among young adults with mental disorders? A systematic review. Aim This systematic review aims to examine and synthesise the evidence for non-clinical services on improving functional outcomes for young adults with mental disorders. Methods The systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results Only 17 studies met the inclusion criteria. Nine studies were focussed on vocational support services and seven of these examined the impact of the well-established Individual Placement and Support model. Most studies reported increased rates of employment of young adults similar to studies in general adult populations. Six studies reported on lifestyle interventions including a combination of physical activities, nutrition education, health coaching and motivation and behaviour change. The measures of functioning used by the studies were too varied to determine whether lifestyle interventions may be useful in improving functional outcomes for young adults. There were only two studies on family and network support services for young adults. Conclusion Given the importance of improving functional outcomes among young adults with mental disorders to improve daily activities, quality of life and recude future disability, further research is needed to understand the impact of non-clinical services on functioning. This evidence will provide pragmatic guidance for service planners to invest in supports and interventions that make a meaningful difference to the lives of young adults living with mental illness.