Loneliness has become one of the most common psychological problems experienced by older adults. Previous studies have indicated that loneliness is correlated with poor physical and psychological health outcomes; therefore, it is important to pay attention to people experiencing loneliness. However, there is a lack of information regarding the prevalence of loneliness, and its associated factors, among community-dwelling older adults in Indonesia, which this study aimed to understand. This study used a cross-sectional, descriptive, and correlational research design. Stratified random sampling was applied to 1360 participants, aged ≥ 60 years, in 15 community health centers in Kendari City, Indonesia. The following questionnaires were used to collect data, including demographic and characteristic information, Short Portable Mental Status Questionnaire, Multidimensional Scale of Perceived Social Support, Geriatric Depression Scale Short Form, and a single-item loneliness question. The prevalence of loneliness among older adults was 64.0%. The multivariate logistic regression showed that older adults who were female, lived with family, had fewer children, had a poor health status, had a poor oral status, had more chronic diseases, had no hearing problems, had poor cognitive function, and had depression had a higher chance of feeling lonely. Loneliness is a serious health issue among the older population in Indonesia. The government, social workers, and healthcare professionals should pay immediate attention to this psychological problem. The study also suggests that appropriate strategies for the prevention of loneliness should be developed in the near future.