Objectives Nursing home residents constituted a vulnerable population during the COVID-19 pandemic, and half of all cause-attributed COVID-19 deaths occurred within nursing homes. Yet, given the low life expectancy of nursing home residents, it is unclear to what extent COVID-19 mortality increased overall mortality within this population. Moreover, there might have been differences between nursing homes in their ability to protect residents against excess mortality. This article estimates the number of excess deaths among Dutch nursing home residents during the pandemic, the variation in excess deaths across nursing homes, and its relationship with nursing home characteristics. Design Retrospective, use of administrative register data. Setting and Participants All residents (N = 194,432) of Dutch nursing homes (n = 1463) in 2016-2021. Methods We estimated the difference between actual and predicted mortality, pooled at the nursing home level, which provided an estimate of nursing home–specific excess mortality corrected for resident case-mix differences. We show the variation in excess mortality across nursing homes and relate this to nursing home characteristics. Results In 2020 and 2021, the mortality probability among nursing home residents was 4.0 and 1.6 per 100 residents higher than expected. There was considerable variation in excess deaths across nursing homes, even after correcting for differences in resident case mix and regional factors. This variation was substantially larger than prepandemic mortality and was in 2020 related to prepandemic spending on external personnel and satisfaction with the building, and in 2021 to prepandemic staff absenteeism. Conclusions and Implications The variation in excess mortality across nursing homes was considerable during the COVID-19 pandemic, and larger compared with prepandemic years. The association of excess mortality with the quality of the building and spending on external personnel indicates the importance of considering differences across nursing home ...