BackgroundMore than one in two older people wake up several times a night to urinate. Far from being a minor inconvenience, nocturia is associated with poor health outcomes. Given the importance of sleep as a foundation for resilience and healthy ageing, nocturia may promote the development of frailty, which is inextricably linked to physical decline, disability, and mortality.The aim of this scoping review was to collate published evidence on the relationship between nocturia and frailty, using the methodological framework of Arksey and O'Malley, together with the Joanna Briggs Institute methodology as guidance (OSF registration: osf.io/d5ct7).MethodsRelevant publications were retrieved via PubMed, Embase, the Cochrane Library and Google Scholar. The Rayyan tool was used to facilitate the screening process. Data were extracted by two independent reviewers. 250 publications were initially identified, of which 87 met the eligibility criteria.ResultsMost of the evidence came from cross-sectional studies, most of which had been published within the last 5 years. The researchers were diverse, with 27% having a geriatric background. Only few publications established a clear association between nocturia and frailty. Other topics included: the association between nocturia and poor sleep quality and duration; the association between sleep and frailty; the association between frailty, multimorbidity, and age-related changes in the lower urinary tract.Conclusion The findings emphasize the increasing interest and interdisciplinary nature of research into the relationship between frailty, nocturia, lower urinary tract symptoms, and sleep disturbances. Further research is required to enhance understanding, establish causality, and identify potential therapeutic approaches.