Key PointsQuestionWhat is the minimal dose of moderate to vigorous physical activity (MVPA) associated with a reduced risk of depression and depressive symptoms in older adults (aged ≥50 years) with and without chronic disease?FindingsIn this cohort study among 4016 older adults, at each of the included time points across a 10-year period, a negative dose-response association was observed between MVPA dose and depressive symptoms and major depression.MeaningThe findings of this study suggest that a lower dose of MVPA than recommended from guidelines for overall health may be associated with a lower risk of depression among older adults.