Objective: To synthesize the evidence on the efficacy of ADHD teacher training interventions for teachers’ ADHD knowledge and reducing pupils’ ADHD-type behaviors. Method: Six electronic databases were systematically searched up to 14/04/20. Meta-analyses were performed to pool standardized mean differences (SMD). Results: 29 studies were included in the systematic review, and 22 meta-analyzed. SMD for teacher knowledge within subjects at post-test and follow-up was 1.96 (95% confidence interval = 1.48, 2.43) and ‒1.21 (–2.02, –0.41) respectively. Between subjects analyses at post-test showed SMD = 1.56 (0.52, 2.59), with insufficient data at follow-up. At post-test, SMD for pupils’ behavior within and between subjects was 0.78 (0.37, 1.18), and 0.71 (–0.11, 1.52), respectively. Medium-to-high risk of bias was found in all but one study. Conclusion: ADHD teacher training programs may be effective in initially improving ADHD teachers’ knowledge. There is inconsistent evidence for their efficacy to reduce students’ ADHD-type behaviors.