The novel coronavirus disease (COVID-19) has had an incisive effect on residents living in long-term care facilities (LTCFs). Local governments have introduced restrictive measures because of the danger posed by this virus. One increasing negative effect of these implementations among residents living in LTCFs is their subjective feelings of loneliness. This study assumed that these measures weighed heavily particularly on residents living in LTCFs, as this group of older people could not decide for themselves whether or how they should be implemented. Thus, this study investigated the retrospectively reported subjective loneliness of residents living in LTCFs. On a large-scale Swiss survey ( = 828; mean age: 87.78, 75% female), residents of 22 LTCFs filled out a questionnaire on their subjective feelings of loneliness during the pandemic. The retrospective loneliness scores of the residents living in LTCFs were found to exceed those reported in other studies focusing on community-dwelling older people. Multivariate regression analyses showed that females, individuals with lower values of joy in life and life satisfaction, and individuals who were not satisfied with the manner in which their care home coped with the COVID-19 measures significantly felt lonelier. Therefore, the subjective feelings of loneliness of residents in LTCFs should be monitored very carefully. As the measures have still not been completely lifted, residents of LTCFs are assumed to still experience social isolation and be at high risk of encountering prolonged feelings of loneliness, which can be detrimental to their mental health and well-being.