Abstract: The U.S. Army’s Ask, Care, Escort (ACE) suicide gatekeeper training has been the annual requirement for all personnel since 2009; however, this training has never been formally evaluated. The present study evaluated three updated versions of ACE: a training for Army leaders (ACE-Suicide Intervention), a training for basic combat trainees (ACE for Basic Combat Training and One Station Unit Training), and a standard training for all personnel (ACE for the Force). Self-report surveys measured pre- to posttraining changes in objective and subjective knowledge and stigma, as well as preparedness, self-efficacy, and likelihood to engage in gatekeeper behaviors. Implementation outcomes, such as training acceptability, suitability, and usability were also assessed. Across these evaluations, participants reported that knowledge and gatekeeper behaviors significantly improved from pre- to posttraining. Implementation metrics revealed a high degree of acceptability and relevance for all three ACE trainings. Overall, the findings of these evaluations suggest important changes in key suicide prevention outcomes following the ACE suite of trainings. Further longitudinal assessment is needed to establish the full effectiveness of gatekeeper interventions in the Army.