•Suicidality in supplemental nutrition assistance program (SNAP) participants is not known.•SNAP could provide a novel setting for reaching those with high prevalence of suicidality.•Suicidality was more common among SNAP participants than nonparticipants.•In fully adjusted age-stratified models, associations remained for those aged <50.•SNAP recipients may benefit from interventions targeting mental health. Suicide represents a substantial public health problem in the U.S. Programs like the Supplemental Nutrition Assistance Program (SNAP)—which provides services for U.S. adults who are food insecure—could be an appropriate venue for suicide prevention strategies targeting high-risk individuals. This cross-sectional study used multiple logistic regression to determine odds ratios (ORs) and 95% confidence intervals (CIs) for suicide ideation, planning and attempt among those who participated in SNAP vs. nonparticipants. The National Survey of Drug Use and Health provided a representative sample of U.S. adults for 2012–2018 (n = 288,730). SNAP participants were more likely than nonparticipants to have serious suicidal thoughts (crude OR=1.89; 95% CI=1.79–1.99), to have a plan for suicide (crude OR=2.35; 95% CI=2.16–2.56) or to attempt suicide (crude OR=2.89; 95% CI=2.54–3.29). Associations remained for those aged <50 in age-stratified analyses that accounted for survey year, demographics, socioeconomic status, self-rated health and mental health service use. SNAP was assessed at the household level; thus, those who reported suicidal thoughts and/or behaviors may not personally interact with SNAP. Using a large, nationally-representative sample of U.S. adults, this study documented greater prevalence of suicide-related outcomes among those who participate in SNAP. Suicide prevention among SNAP participants may provide a unique means to reach individuals who are often hard to engage in other health services.