Death by suicide is a serious and growing public health concern in the United States. This noncontrolled, naturalistic study examined professionals' knowledge about suicide and confidence in working with suicidal individuals, comparing those who had received either of two gatekeeper trainings-Question, Persuade, and Refer (QPR) or Applied Suicide Intervention Skills Training (ASIST)-or other suicide-relevant training or no training.Participants (N=16,693) were individuals in various professional roles in the field of behavioral health care in Indiana, Kentucky, New York, Pennsylvania, Tennessee, Texas, and Utah. Participants completed a survey assessing suicide knowledge and skills confidence.Most participants (52.9%) reported no previous suicide prevention or assessment training. Individuals with suicide-relevant training demonstrated greater suicide knowledge and confidence than those with no such training. Among those who had received any training, no differences were found in suicide knowledge; however, individuals who had received ASIST reported greater confidence in working with suicidal individuals, compared with those who had received other training. Professional role and prior experience with a client who had died by suicide had significant positive relationships with suicide knowledge and confidence. Regional differences emerged between states and are examined within the context of statewide suicide prevention initiatives.Increasing access to and incentives for participating in suicide-relevant training among behavioral health care staff may foster a more knowledgeable and confident group of gatekeepers. Future research should examine whether increases in knowledge and confidence among staff translate into actual changes in practice that help protect and serve at-risk individuals.