This systematic review synthesizes current evidence to determine how subjective cognitive impairment (SCI) relates to physical, cognitive, and social activity participation in older adults. Nine peer-reviewed articles were reviewed and appraised for evidence quality. Most were cross-sectional and had high methodological quality. Higher levels of SCI were almost universally associated with lower levels of physical and social activity participation. These findings suggest that older adults who report higher SCI engage in fewer activities. Examining these relationships longitudinally is an important next step to determine whether SCI precedes withdrawing from activities in older adults.