Although insomnia symptoms are associated with risk of suicide ideation, the means by which insomnia influences ideation, as well as the role depression plays in these relationships, require further study. In this study, we examined whether certain socio-cognitive variables (fatigue, social problem-solving, and hopelessness) in conjunction with depression explained this relationship among female college students. Methods 483 female students completed measures assessing insomnia and depressive symptoms, fatigue, social problem-solving ability, hopelessness, and suicide ideation. Results Path analyses indicated that socio-cognitive variables partially explained the insomnia-ideation relationship above the influence of depressive symptoms. Higher depressive symptoms exacerbated relationships between social problem-solving and hopelessness, heightening ideation risk. Conclusions Our findings expand knowledge of intermediate socio-cognitive variables that may contribute to the insomnia-ideation relationship, and indicate that clinically-severe depressive symptoms compound the contribution of negative self and future appraisals to thoughts of suicide. Suicidal females with insomnia and depressive symptoms may benefit from interventions targeting problem-solving skills and improving sleep.