As global population ageing persists, understanding older adults' capacity to navigate the financial and healthcare system is essential. This scoping review examines how the concept of financial health literacy (FHL) is described and measured in the existing literature, the factors that may affect it, and its potential outcomes in middle‐aged and older adults. The review follows the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta‐Analysis) extension guidelines to synthesise the available evidence on this topic. We utilised electronic databases and hand searching to identify relevant literature published between 2010 and 2022. A total of 29 articles were included in this review. The results showed that FHL involved accessing, understanding and utilising financial information for planning/management of healthcare expenses and selecting appropriate health services. However, FHL is not particularly depicted as a concept in the current literature, as most studies investigated health literacy, financial literacy and health insurance literacy as separate domains that were interrelated to one another. No validated measurement tool was developed for FHL. We propose five domains to indicate the concept and measurement of FHL in middle‐aged/older adults: money management, management of medical bills, understanding health insurance, deciding on appropriate health services, and planning for long‐term care needs. Demographic variables, such as sex (females), advanced age, cognitive impairment, low education and income and racial and ethnic minorities, were found to be related to low FHL. The reviewed studies also showed that FHL was related to several outcomes, including healthcare decision‐making, physical health and psychological well‐being. Hence, future studies to develop and validate assessment tools of FHL, together with the involvement of vulnerable groups, are imperative to understanding the concept of FHL. This could also facilitate the development of appropriate interventions that could enhance this capacity in the ageing population.