Aging is associated with decline in executive function that may lead to reduced dual-task performance. Regular exercise has been recommended for promoting or maintaining mental and physical health in older adults, yet only a fraction of older adults exercise regularly. Exergame training may have the potential to enhance exercise adherence. Therefore, the aim of this study was to examine the effects of exergame-based dual-task training on executive function and dual-task performance in community-dwelling older adults. This was a single-blinded, randomized-controlled trial. Twenty community-dwelling older adults were recruited and randomly assigned to one of two groups. All participants completed 36 trainings, including three 60-minute sessions/week over 12 weeks. Participants in the experimental group received exergame-based dual-task training, while those in the control group received home-based multicomponent exercise training. Measures of executive function, dual-task performance, and community walking ability were assessed before and after the intervention. Significant group × time interactions ( = 0.000-0.027) with large effects were found in all selected outcome measures. Compared with the control group, the experimental group improved significantly in measures of general executive function ( = 0.014), inhibitory control ( = 0.037), cognitive dual-task performance ( < 0.001), and community walking ability ( = 0.002). Enhanced general executive function was highly correlated with either improved motor dual-task performance ( = 0.674) or improved cognitive dual-task performance ( = -0.701). These results suggested that exergame-based dual-task training improved both executive function and dual-task performance in older people. These positive effects could be transferred to enhance community walking ability. Clinical Trial Registration number: ACTRN 12617000095369.