Existing literature highlights notable health and social inequalities for people ageing with a lifelong disability and the need for research to better understand how we can support this group to age well. This scoping review mapped existing literature related to 'ageing well' in people with lifelong disabilities. Five scientific databases and grey literature sources were searched for studies related to 'ageing well' and 'lifelong disability' (defined as a disability that a person had lived with since birth or early childhood). We identified 81 studies that discussed ageing well with a lifelong disability, with most (70%) focusing on intellectual disabilities. Two themes captured existing research on ageing well with a lifelong disability: 1.) Framing ageing well with a lifelong disability, which included the ways that people with lifelong disability, their supporters and existing research frame ageing well for this group and 2.) Supporting people to age well with a lifelong disability, which involves the micro, meso and macro-level factors where research suggests interventions to facilitate ageing well could be situated. This synthesis highlights how ageing well is currently framed in the literature and where interventions to improve ageing well in this group could be situated. Literature highlights the importance of considering multi-level interventions to improve ageing well. Evidence gaps include the lack of research conducted with groups other than those with intellectual disabilities and the need for more research examining ageing well interventions.