Autistic people have higher rates of both physical and mental health conditions, as well as significantly lower life expectancy than the general population. Despite limited research, ‘autistic burnout’ is described by many autistic people in personal accounts, highlighting its wide-ranging impact on quality of life and links to poor mental health and suicide. Research in the general population recognises burnout as a work stress-associated syndrome. Little is known, however, about what (combination of) factors contribute to burnout for autistic people, whether it is the same syndrome, which supports help, and how environments can best be adapted to prevent or alleviate it. Therefore, this study will explore what burnout is, in autistic populations, and factors that contribute to it. The way people think (e.g., attention to detail), the co-occurring conditions they have (e.g., depression), the kinds of environments they find themselves in, and how other people treat them, may all contribute to vulnerability or resilience to burnout and related mental health difficulties. By exploring energy depletion and burnout in diverse autistic populations, via multiple methods including standardised questionnaires, interviews, focus groups and experiments, this study aims, firstly, to describe and measure autism-related burnout. Secondly, it aims to shed light on factors that contribute to it. Thirdly, the project will create accessible resources – including a website built on research and expert-by-experience evidence – disseminating information on fatigue and burnout experiences of autistic people, and what they report as helpful to prevent or treat burnout, in order to improve autistic people’s quality of life.