Immunological aging, which encompasses age-associated declines in the immune system (immunosenescence) and increases in inflammation (inflammaging), is associated with morbidity and mortality. A growing body of research suggests stress is one factor that may accelerate immunological aging. This article provides a brief overview of immunological aging, describes key biological pathways acting at multiple lifespan stages linking stress and immunological aging, and reviews recent innovative work characterizing associations between stress in several domains and immunological aging, as well as potential protective and risk factors. Important directions for future research include careful characterizations of the complexities of stress and rigorous measurement of immunological aging processes. Advancing knowledge of stress resilience and healthy immune aging may ultimately slow disease onset and extend healthspan.