The proportion of households living in condominiums in Japan is increasing. With the country’s aging society and declining birthrate, Japanese cities have undergone structural reforms to become “compact cities.” Accordingly, the author explored the relationship between urban compactness and condominiums based on condominium locations in cities. In this study, 161 municipalities in Japan that have determined and announced a Location Normalization Plan until 2018 and have implementing densely populated areas are extracted and analyzed. Data from the 2020 and 2015 censuses were used to define households living in owner-occupied and communal housing as “condominium households” and to analyze the relationship between urban compactness and condominiums. Results showed a correlation between urban compactness and condominium locations in large and medium-sized cities. To promote compact cities in the future, guidelines for establishing condominiums and appropriate maintenance and management of existing condominiums must be set according to the characteristics of the city.