Objective Despite high suicide mortality in U.S. jails, little is known about the cognitive (ideation) and behavioral (attempt) spectrum of suicide risk in this population. Identifying factors associated with the development of suicidal ideation, as well as the translation of thoughts to acts of suicide, is important for suicide prevention. Method Using data from a cross-sectional study conducted in 2018–2019, we investigated suicidal ideation and attempt among 548 individuals incarcerated in jail in the United States. Specifically, we compared those with suicidal ideation (n = 212) to those without suicidal ideation (n = 336), as well as compared those who had experienced suicidal ideation and attempted suicide (n = 114) to those who thought about suicide without making an attempt (n = 98), on a range of sociodemographic and clinical factors. Results Over one-third (38.7%) of participants had a history of suicidal ideation, whereas 23.3% had attempted suicide. In the adjusted analyses, a family history of suicide (OR = 2.09), drug use (OR = 2.26), social support (OR = 0.61), and self-harm (OR = 24.93) were linked to suicidal ideation. No wish to live (OR = 5.26) and interpersonal violence while intoxicated (OR = 2.41) were associated with the progression from suicidal ideation to a suicide attempt. Conclusions Consistent with extant theoretical and empirical work, findings suggest that factors linked to the development of suicidal cognitions differ from those underlying the progression from suicidal ideation to a (non-lethal) suicide attempt. HIGHLIGHTS Suicidal risk is particularly high among individuals who are incarcerated in jail. Factors linked to suicidal ideation differ from those underlying acts of suicide. Ideators and attempters possess a different set of targets for intervention.