Peer support in mainstream high schools may help neurodivergent young people to thrive and navigate challenging experiences. Previous research with diagnosis-specific neurodivergent cohorts indicates that peer support can help improve wellbeing, strengthen social identity and school belonging, and may alleviate pressure to conform to neurotypical social norms. In the light of a call for peer support for all neurodivergent people, rather than diagnosis-specific support, the aim of this study was to identify key elements of a neurodivergent student-led peer support programme via a co-design process. The co-design groups included neurodivergent young people and adults who work with them. Transcripts from a series of design meetings were thematically analysed and three main themes were identified: the central role of the peer support group facilitator; inclusiveness is essential; and directly addressing negative perceptions of others. The study emphasised that a co-design methodology is crucial to ensure that the end-users’ voices and perspectives are embedded in the design. Overall, the co-design teams recommended implementing neurodivergent student-led peer support for neurodivergent young people attending mainstream schools to promote inclusivity and prioritise the expertise of neurodivergent students. This type of support may benefit neurodivergent young people by encouraging them to build community and provide and receive peer support in a space that centres neurodivergent comfort and authenticity, rather than depending on applying neurotypical social norms. Lay Abstract Neurodivergence is a term used to describe people who may think, feel, and process the world differently than the majority. It includes conditions such as autism, attention deficit hyperactivity disorder (ADHD), and dyslexia. Many neurodivergent young people struggle in school, and some autistic adults have shared that having support from other neurodivergent peers would have improved their school experience. Other research shows that peer support can improve wellbeing, self-advocacy skills, social identity and a sense of belonging for neurodivergent young people. In this study, the authors along with a group of neurodivergent young people and a group of adults who work with neurodivergent young people, created a peer support programme, to be led by neurodivergent students, specifically for neurodivergent young people who attend mainstream high schools. The aim of this study is to identify which elements of a peer support programme are important to neurodivergent young people themselves. We analysed the transcripts from the co-design meetings and found three main themes: the central role of the peer support group facilitator; inclusiveness is essential; and directly addressing negative perceptions of others. Overall, using co-design methods to create a peer support programme is crucial to ensure the voices and perspectives of those who will use it are integrated into the design. The co-design team felt that peer support led by neurodivergent students would be inclusive and may allow students to feel able to be themselves at school.