There is a scarcity of studies examining the impact of the COVID-19 pandemic on the descendants of immigrants, a group representing a growing segment of the population in many countries. This study utilized a national cohort event history analysis in Sweden, consisting of all residents aged over 20 years at the end of 2019 (n = 7 871 444), with a follow-up period from 31 December 2019 to 1 June 2021. Poisson regression was used to estimate incidence rate ratios for severe COVID-19 morbidity [hospitalization, intensive care unit (ICU) admission] and COVID-19-related mortality based on generation status [first generation (G): foreign-born, arrived as adults; the 1.5 generation: foreign-born, arrived as a child; second generation: native-born to two foreign-born parent; and 2.5 generation: native-born to one foreign-born parents] stratified by their region of origin (Nordics, Global South, and Global North) using the majority population (two native-born parents) as reference. All immigrant generations experienced higher rates for severe COVID-19 morbidity compared to the majority population. While this pattern is observed across all regions of origin, the largest differences appear among individuals with a Global South background. Adjusting for social and health factors moderately attenuates the estimates for the descendants of immigrants. Mixed results are found regarding COVID-19 mortality by region of origin and generational status. All immigrant generations experience a COVID-19 morbidity burden comparable to first-generation immigrants and should thus be considered when planning preventive measures to prepare for future pandemics and health crises.