Senescent cells play important roles in various biological processes that promote fitness and health; however, their timely elimination by immune cells is critical to maintain tissue homeostasis and prevent disease. Despite this, senescent cells accumulate systemically with age, suggesting that certain immune cells also become senescent and dysfunctional during aging. In support of this, we previously demonstrated that CD8 T cells, immune cells capable of targeting senescent cells, increasingly develop characteristics of senescence with advancing age in humans. Here, we characterized the senescence state of human SA-βGal-expressing (SA-βGal^high) CD8 T effector memory (EM) cells, their functional capabilities, and their enrichment in aging and disease.