A key measure of the effectiveness of end-of-life care is the place of death. The coronavirus disease 2019 (COVID-19) pandemic affected end-of-life care and the circumstances of patients with dementia. This observational, retrospective cohort study used Japanese national data to examine the numbers and locations of reported deaths among patients with dementia older than 65 years during the COVID-19 pandemic. Locations were grouped as medical institutions, nursing facilities, homes, or all settings. The quasi-Poisson regression model known as the Farrington algorithm was employed. Between December 30, 2019, and January 29, 2023, 279,703 patients who died of causes related to dementia were reported in Japan. A decline was seen in early 2020, followed by increased numbers of deaths in homes, medical facilities, and nursing homes beginning in October 2020, December 2020, and March 2021, respectively. In 2021, the percentage of excess deaths at home peaked at 35.2%, while in 2022, those in medical facilities and nursing homes peaked at 18.8% and 16.6%, respectively. In 2022, the percentage of excess deaths in nursing homes exceeded that of other locations. The results suggest a change in the preferred place of death, along with pandemic-related visitation restrictions among healthcare facilities. Excess deaths also suggest strained medical resources and limited access to care. Methodological limitations include data from a limited period (2017 onwards) and post-2020 data used to estimate data after 2021, albeit with weighting. Considering these findings, physicians should reconfirm preferred places of death among older patients with dementia.