Acceptance and commitment therapy is an emerging evidenced-based practice, but no systematic review regarding the effects of ACT on family caregivers has been conducted. This article examined the effects of ACT on family caregivers by conducting meta-analysis with a random effects model. Twenty-four articles were identified from four electronic databases searched up to 30 March 2020. Meta-analyses found moderate effects of ACT on depressive symptoms and quality of life, small effects on anxiety, and small to moderate effects on stress. Further ACT studies should be conducted to measure effects on different outcomes for various family caregiver populations.