Background Veterans' success with navigating the challenges of transition from military service may contribute to their risk for suicidal outcomes. The concept of well-being can help to conceptualize and assess successful navigation of reintegration challenges and may serve as an optimal target for public health-oriented suicide prevention. Methods The relationship between US veterans' psychosocial well-being and experiences of suicidal ideation (SI) during the first 3 years following military separation was evaluated using multinomial logistic regression predicting SI trajectories over time in a population-based, longitudinal, post-9/11 veteran cohort. At 3-months post-separation, veterans reported on their socio-material conditions, functioning, and satisfaction with respect to vocational, financial, and social domains. SI frequency was assessed at 3-, 9-, 15-, 21-, and 27-months post-separation using the Patient Health Questionnaire-9. Results Veterans' vocational, financial, and social well-being were associated with their SI trajectories, even after accounting for mental health. Socio-material conditions, functioning, and satisfaction all emerged as important predictors of SI trajectories, although results varied across domains. Effects were largest for social well-being. Conclusions Suicide prevention efforts may benefit from a holistic approach that considers veterans' needs for support across their vocational, financial, and social well-being, inclusive of their socio-material conditions, functioning, and satisfaction within each domain.