IntroductionThis study aimed to investigate the mechanisms of the development of suicidal ideation and its moderating and protective factors. Drawing on the Interpersonal‐psychological theory of suicide, we proposed that disruptions to belongingness, in conjunction with tolerance of health risk, may influence the development of suicidal ideation above and beyond psychosocial changes such as disruptions to finances and work.MethodsThe study involved a longitudinal investigation of an Australian representative sample reporting suicidal ideation fortnightly for 12 weeks between March and June 2020.ResultsThe results indicated that participants who reported higher levels of belongingness, mastery, and intolerance of health risk were less likely to experience suicidal ideation and had lower severity of suicidal ideation. Mastery significantly strengthened the negative link between belongingness and the incidence of suicidal ideation, while agreeableness significantly strengthened the negative link between belongingness and the severity of suicidal ideation over time.ConclusionThe findings suggest that supporting effective social connectedness during times of isolation and promoting self‐efficacy, mastery, and regulation of risk tolerance, may be crucial for suicide prevention and therapeutic intervention.