Introduction Perceived social support is a well-established protective factor against suicidal ideation, yet few studies have examined how actually seeking social support relates to suicidal ideation. We investigated the contexts under which social support seeking may be related to greater, or lesser, suicidal ideation. Methods Undergraduates completed ecological momentary assessments up to 6 times daily. Multi-level moderated logistic regressions examined interactions between presence of daily-level support seeking with burdensomeness and loneliness as indicators of same-day and next-day suicidal ideation. Results Seeking social support was positively associated with same-day, but not next-day reports of suicidal thinking. On days when participants felt burdensome and sought support, they had greater odds of reporting suicidal ideation (OR = 1.659, 95% CI = [1.420, 1.938]), compared with days they felt burdensome but did not seek support. There was no effect of burdensomeness on next-day ideation. There was no significant interaction effect between support seeking and loneliness on same-day or next-day ideation. Conclusions Seeking support and feeling like a burden are associated with a greater likelihood of experiencing suicidal ideation. The current results underscore the importance of equipping at-risk individuals with a toolbelt of a variety of coping skills.