To promote school safety across K-12 settings, one preventative approach to school violence is school-based threat assessment. The current study utilizes a systematic review of empirical threat assessment investigations to inform evidence-based practices for school threat assessment. Twenty-three articles met inclusion criteria for the review. The primary threat assessment framework utilized within the identified studies was the Virginia School Threat Assessment Guidelines and its revised version, the Comprehensive School Threat Assessment Guidelines. Despite evidence supporting the use of CSTAG in schools, limitations include racial disproportionality within disciplinary outcomes and threat identification. Overall, there was minimal evidence of implementation fidelity of the threat assessment frameworks, highlighting the need for fidelity measures to evaluate threat assessment implementation in schools. Future research and implications are discussed.