Adults with autism face high rates of unemployment. Supported employment enables individuals with autism to secure and maintain a paid job in a regular work environment. The objective of this study was to assess the cost-effectiveness of supported employment compared with standard care (day services) for adults with autism in the United Kingdom. Thus, a decision-analytic economic model was developed, which used outcome data from the only trial that has evaluated supported employment for adults with autism in the United Kingdom. The main analysis considered intervention costs, while cost-savings associated with changes in accommodation status and National Health Service and personal social service resource use were examined in secondary analyses. Two outcome measures were used: the number of weeks in employment and the quality-adjusted life year. Supported employment resulted in better outcomes compared with standard care, at an extra cost of £18 per additional week in employment or £5600 per quality-adjusted life year. In secondary analyses that incorporated potential cost-savings, supported employment dominated standard care (i.e. it produced better outcomes at a lower total cost). The analysis suggests that supported employment schemes for adults with autism in the United Kingdom are cost-effective compared with standard care. Further research needs to confirm these findings.