Despite numerous studies that have demonstrated widening social inequalities during the COVID-19 pandemic, we do not yet see research on whether the surge in social inequalities would also have unequal consequences for people’s subjective experience. By linking the countrywide Understanding Society COVID-19 longitudinal survey with the latest wave of the main-stage survey, we examine whether and how the psychological costs of economic lockdowns are unevenly distributed between UK-born and foreign-born working men. Findings provide direct evidence for a widening gap in mental well-being resulting from the widening socioeconomic gap between immigrant and native-born working men, during COVID-19 lockdowns. Employment disruption does not necessarily hurt mental well-being of the native-born, as long as their income is protected. For immigrants, however, work hour reduction is generally accompanied by psychological costs, with greater mental suffering among immigrant men who experience work hour reduction without income protection–particularly in the extreme scenario of reduction to no work hours. © 2020 European Sociological Association.