When families are engaged in their education, children's academic, behavioral, and social-emotional development is indirectly supported. Many teacher-training programs (TTPs) focused on preparing teachers to communicate and work with families have been developed, although inconsistencies regarding their effectiveness exist. The current meta-analysis of 39 studies systematically analyzed the effects of TTPs on teachers' family-engagement practices, attitudes, and knowledge. TTPs included preservice university courses, teacher in-service, and professional development programs. Studies were coded for key sample, setting, and quality characteristics. Analyses revealed TTPs had a significant positive effect on all teacher family-engagement outcomes. Key intervention components were also determined (e.g., communication strategies, collaborative planning, and problem solving) and can be used to inform the development of future TTPs. Although results are promising, future TTPs should aim to improve methodological rigor and study quality.