Objectives Today, the issue of older adults' well-being has become a serious challenge of policy-making and a key subject of researches. The complexity, multidimensionality, and multileveled nature of the concept of well-being have resulted in numerous objective and subjective indexes at the micro and macro levels. The aim of the article is to assess and measure the well-being of Iranian elderly using the Age-Watch index. Methods & Materials The method of the study was a secondary analysis of various data sources using Excel and SPSS v. 25 software in the methodological framework of the Global AgeWatch index. This method assesses the well-being of Iranian older adults at the national and provincial levels for 2016. The index provides a holistic view of older people's lives in four dimensions included income security, health status, capability, and the enabling environment. Results The results indicated the significant provincial differences in the AgeWatch index and its various dimensions, especially income security, and health status. The AgeWatch index scores ranged from 6.5 in Sistan and Baluchestan province to 77.9 in Tehran province. In general, the highest rank goes to the provinces of Tehran, Semnan, and Fars, respectively, and the lowest rank goes to the provinces of South Khorasan, Ilam and Sistan and Baluchistan, respectively. The results showed a significant correlation between AgeWatch index and human development index in Iran. In addition, the results showed Iran is ranked 64th among 97 countries in AgeWatch index. Iran was the best in terms of health status (43rd) and worst in terms of capacity dimension (88th). Conclusion Economic and social policies supporting the employment, income, health, and independence of older adults play an important role in increasing the well-being and welfare of older adults. Therefore, dimensions of financial security, such as the development of universal coverage of pensions and poverty reduction, as well as capacity dimension, such as providing elderly self-employment and promoting the education and training of the elderly, should be a policy priority. [ABSTRACT FROM AUTHOR]