Subjective age has been shown to reliably predict a variety of psychological and physical health outcomes, yet our understanding of its determinants is still quite limited. Using data from the Aging as Future project, the authors examined the degree to which views of aging influence subjective age and how this influence varies across cultures and domains of everyday functioning. Using data from 1,877 adults aged from 30 to 95 years of age collected in China, Germany, and the United States, they assessed how general attitudes about aging and perceptions of oneself as an older adult influenced subjective age estimates in 8 different domains of functioning. More positive attitudes about aging were associated with older subjective ages, whereas more positive views of self in old age were associated with younger subjective age. It is hypothesized that these effects are reflective of social-comparison processes and self-protective mechanisms. These influences varied considerably over contexts, with views of aging having a greater impact in domains associated with stronger negative stereotypes of aging (e.g., health) compared to those with more positive ones (e.g., family). Culture also moderated the impact of aging views in terms of the strength of prediction, direction of effect, and age of greatest influence, presumably due to cultural differences in the salience and strength of aging-related belief systems across contexts. The results illustrate the contextual sensitivity of subjective age and highlight the role played by an individual’s views of old age—both in general and regarding oneself—in determining their own experience of aging.