This cross-sectional study investigated osteosarcopenia prevalence and its correlates among 2142 adults aged 55 and older in Finland. Findings show 3.9% had osteosarcopenia, while 13.8% and 11.1% had probable sarcopenia only or osteoporosis only, respectively. Osteosarcopenia was associated with low BMI, impaired mobility, ADL limitations and depression. Sarcopenia appeared to drive these associations more than osteoporosis. Osteosarcopenia may be a risk factor for functional decline, hospitalization, and institutionalization, warranting further research.