Previous diary work indicates that older people experience more intrusive and unwanted thoughts (i.e., cognitive interference) on days with stressors. We examined additional predictors of daily cognitive interference to enhance understanding of the psychological context surrounding this link. We specifically focused on factors related to subjective experiences of aging based on studies that have related higher stress and impairments in cognition such as executive control processes (working memory) to negative age stereotypes. Consistent with these findings, we generally expected stronger stress effects on cognitive interference when daily self-perceptions of aging (i.e., within-person fluctuations in awareness of age-related losses [AARC losses]) and general aging attitudes (i.e., individual differences in attitudes toward own aging [ATOA]) were more negative. Participants (n = 91; aged 60-80) on Amazon's Mechanical Turk completed surveys on 9 consecutive days, reporting on their ATOA (Day 1) as well as their stressors, AARC losses, and cognitive interference (Days 2-9). Multilevel models showed that people reported more cognitive interference on days with more AARC losses. Individuals with positive ATOA also experienced less cognitive interference on days with more stressors, whereas those with negative ATOA experienced more. Both individual differences and fluctuating daily perceptions of aging appear to be important for older adults' cognitive interference. Consistent with other work, positive ATOA protected against daily stressor effects. Further elucidating these relationships can increase understanding of and facilitate efforts to improve (daily) cognitive experiences in older adults.