Suicide is an important social and medical problem worldwide, including in countries that use traditional East Asian medicine (TEAM). Herbal medicine (HM) has been reported to be effective against several suicide-related conditions. This systematic review aimed to investigate the efficacy and safety of HM in reducing suicidal behavior including suicidal ideation, attempts, or completed suicide. We conduct a comprehensive search in 15 electronic bibliographic databases from inception to September 2022. All types of prospective clinical studies—including randomized controlled clinical trials (RCTs)—involving HM without or with routine care are included. The primary outcomes of this review are validated measures of suicidal ideation including the Beck scale for suicidal ideation. The revised Cochrane’s risk of bias tool and other tools including the ROBANS-II tool are used to assess the methodological quality of RCTs and non-RCTs, respectively. A meta-analysis is performed using RevMan 5.4 in cases of homogeneous data from controlled studies. The results of the systematic review provide high-quality evidence to determine the efficacy and safety of HM for suicidal behavior. Our findings are informative for clinicians, policymakers, and researchers, aimed at reducing suicide rates, especially in countries that use TEAM.