We attempted to disentangle the interrelations between hopelessness, loneliness, and suicidal ideation, by comparing two conceptually driven models of their relationships, prospectively among 234 undergraduates, using a series of multiple regression/correlation equations. Model 1 framed loneliness as a risk factor for future suicidality that operates via its influence on hopelessness (the mediational view). Model 2 viewed hopelessness as a source variable that is predictive of both loneliness and suicidality, and postulated no relation between loneliness and suicidality beyond hopelessness. Model 2 received support, whereas Model 1 did not. We discuss the implications of our findings for the nomological status of hopelessness and loneliness as correlates of suicidality, and for exploration of the structural interrelations of suicide-related variables in general.