BackgroundIt is common for older people to become grandparents in later life. However, the impacts of grandparenting on their health and well-being remain ambiguous, especially in Chinese society, where the family is in the core of culture. The current study explored the relationship between grandparenthood and Chinese older people’s health and psychological well-being in Hong Kong. MethodsCross-sectional data were collected from a sample of 1,208 Hong Kong Chinese older people aged 55 and above through a telephone survey conducted in 2019. Participants were grouped into three categories: current grandparents (n = 507), grandparents-to-be (n = 275), and grandparents-not-to-be (n = 426). Multivariate linear regressions were performed to examine the relationship between grandparenting status and health and well-being outcomes, including self-rated physical health, mental health, resilience, and happiness. The potential moderating roles of older adults’ demographic characteristics, including age, sex, education, marital status, financial status, were also examined. ResultsBivariate analyses suggested statistically significant differences between health and well-being across the three groups of participants. Regression models showed that, compared with grandparents-not-to-be, being a current grandparent was associated with a significantly higher happiness level. Being a future grandparent was associated with significantly higher levels of happiness, resilience, and self-rated physical health. Moderating analyses showed that age, marital status, and educational level could moderate the relationship between grandparent status and resilience and self-rated mental health. ConclusionsThe current study offers preliminary insights into the significant relationship between grandparenthood and older adults’ health and well-being. It calls for future studies to further explore the mechanisms between grandparenthood and the healthy ageing of different subgroups of older adults.