Loneliness is considered a major issue, often negatively influencing the quality of life of individuals of all ages, and of older adults, in particular. The aims of this study are: (1) to assess the association between close social relationships and loneliness; and (2) to examine the moderating role of subjective age in this association. Married or cohabiting community-dwelling Israelis in the second half of life (N = 360) were interviewed and reported on their close social relationships, their level of loneliness, and their subjective age. The number of close social relationships was found to have a negative relationship with loneliness. Moreover, subjective age was found to moderate the relationship between close social relationships and loneliness, such that the association was weaker for those with older subjective age. Those with older subjective age are often not able to benefit from close social relationships to alleviate loneliness as much as their younger-subjective-age counterparts. Efforts to address older adults’ loneliness should consider focusing on older adults’ perceptions of aging.