Guided by the theory of stress proliferation, our study examined whether loneliness, citizenship status, and English proficiency were associated with psychological distress among older adults, and if citizenship status and English proficiency moderated these relationships. Using the older adult subsample (65+ years) of the 2019-2020 California Health Interview Survey (N = 15,210), we assessed cross-sectional associations between loneliness, citizenship status, and English proficiency on psychological distress by conducting multivariable linear regression models. Interaction terms were included in subsequent models to determine if citizenship status and English proficiency moderated the relationship between loneliness and psychological distress. In unadjusted models, greater loneliness was associated with higher distress. Both naturalized citizens and noncitizens, and those with limited English proficiency (LEP) exhibited greater distress than US born citizens and those who speak English only (EO). After adjusting for sociodemographic and health covariables, loneliness remained significant for distress although the relationships between citizenship status and English proficiency became attenuated. With the inclusion of interactions, the magnitude of the relationship between loneliness and distress was stronger for naturalized citizens and those with LEP than native-born citizens and those who speak EO, respectively. Loneliness was the most consistent stressor affecting multiple life domains. However, our findings demonstrate that stress proliferation is occurring among older immigrant adults and the interplay between loneliness, citizenship status, and English proficiency is contributing to heightened distress. Further attention is needed in understanding the role of multiple stressors influencing mental health among immigrant older adults.