As the global aging trend increases, older adults are placing greater emphasis on their health. Evidence indicates that there is a complex association between house prices and older adults’ health, with their subjective well-being potentially acting as a mediator in this connection. A mediation model, utilizing data from China’s 2018 Labor Dynamics Survey, was employed to examine the impact pathway of house prices, subjective well-being, and self-rated health, while investigating the differences between young-old and old-old groups. The major findings are as follows: (1) House prices negatively affected self-rated health among the older adults. (2) The subjective well-being of older adults mediated the pathway through which house prices affected their self-rated health. (3) For old-old adults, higher house prices were more strongly linked to an increased likelihood of reporting good, very good, or excellent health. Subjective well-being was more significantly associated with reporting better health among the young-old group. Compared with the young-old population, the impact of house prices on self-rated health was stronger among the old-old, and the degree increased with increasing age. Consequently, to improve older adults’ well-being and self-rated health, effective healthy-aging policies should not only consider the influence of the real estate market, but also balance the allocation of elderly service facilities, promote affordable housing, and implement a combination of medical and nursing care from the perspective of urban planning.