Antidepressant non‐adherence among people with depressive disorder is a major, ongoing public health issue, yet few studies have focused on older adults and their medication adherence. Although treatment adherence is determined by multiple factors, one of the important and modifiable predictors are patients’ attitudes and beliefs about medication. We explored a sample of 135 older Chinese people with major depression, and the relationship between beliefs about antidepressants and medication adherence. Sociodemographic and illness variables were also examined. In all, high antidepressant adherence was reported in 37.8%, moderate adherence in 39.2%, and low adherence in 23%. Ordinal regression analysis showed perceived necessity (P < 0.01) and concern (P < 0.01) about antidepressants were significant influencing factors. Other variables with a positive association with higher adherence were lower average income (P < 0.05), fewer number of prior episodes of depression (P < 0.01), and comorbid anxiety (P < 0.05). The present study highlights low adherence in a sample of older depressed Chinese people, and highlights how beliefs about medication affect adherence. Therefore, more attention should be focused on non‐adherence in older patients, and there is a need to establish accessible and systematic education programmes to correct misconceptions to improve their adherence.