Preventing and reducing domestic violence is a national and international social priority. Civil law protection orders (POs) have been the primary legal response to domestic violence internationally for a number of decades. However, evidence of their effectiveness is mixed due to variations in application within and across countries and variable quality of the research with most studies at high risk of bias. The purpose of this systematic review and meta-analysis was to evaluate the effectiveness of POs in reducing violation rates of domestic violence, compare violation rates reported by victims and police reports, and identify factors that influence violation and reoffense. Two electronic databases were searched; two independent researchers screened abstracts. Data were collected and assessed methodologically, using the Kmet Checklist Appraisal Tool and National Health and Medical Research Council Hierarchy of Evidence. Twenty-five studies that evaluated the effectiveness of POs in reducing recidivism in domestic violence met the eligibility criteria. Meta-analyses of weighted means of violation in the studies were conducted. Violation rates were found to be higher for victim reports compared with police reports. Violation rates were reduced when POs used in combination with arrests. PO violation rates were lower among perpetrators without histories of arrest for committing violence, perpetrators not engaging in stalking, and where couples have had medium to high incomes. There is no consensus among the studies about what the most appropriate methodology is to measure PO effectiveness. Future research should establish a more unified approach to evaluating the effectiveness and violations of POs.