•Cross-sectional study of 108 veterans who experienced military sexual trauma (MST).•75% with post-MST suicidal ideation (SI); 40.7% with post-MST suicide attempt (SA).•Posttraumatic cognitions about self associated with post-MST SA/SI and past-week SI.•Pre-MST SI associated with post-MST and past-week SI; pre-MST SA with post-MST SA.•Childhood physical abuse and military sexual assault also related to post-MST SI. As increasing research demonstrates that military sexual trauma (MST) is associated with suicidal ideation and attempts, discerning factors that place MST survivors at risk for these outcomes is critical. The present study aimed to: (1) characterize suicidal ideation and attempts among MST survivors; (2) identify factors associated with post-MST suicide attempts, post-MST suicidal ideation, and past-week suicidal ideation. A convenience sample of 108 veterans (66 women, 42 men) who reported a history of MST participated in this cross-sectional study. Pre-MST suicidal ideation and attempt, childhood physical and sexual abuse, military sexual assault, institutional betrayal, and posttraumatic cognitions about self, world, and self-blame were examined, with age and gender as covariates. Seventy-five percent of participants reported experiencing post-MST suicidal ideation, and 40.7% reported attempting suicide following MST. Pre-MST suicide attempt and posttraumatic cognitions about self were associated with post-MST suicide attempt. Pre-MST suicidal ideation, military sexual assault, childhood physical abuse, and posttraumatic cognitions about self were associated with post-MST suicidal ideation. Lastly, pre-MST suicidal ideation and posttraumatic cognitions about self were associated with past-week suicidal ideation; results were unchanged when accounting for recent PTSD or depressive symptoms. The cross-sectional design, retrospective self-report, and small sample are limitations. Addressing negative posttraumatic beliefs about self may be important for managing suicide risk among MST survivors. Assessing for pre-MST suicidal ideation and attempt is likely also warranted. Further understanding of the longitudinal impact of posttraumatic beliefs about self on subsequent risk for suicidal ideation and attempt is warranted.