This study examines how relationship quality in family and peer domains are associated with suicidal ideation (SI) in youth with bipolar disorder (BP). We assessed 404 Course and Outcome of Bipolar Youth study participants for psychiatric disorders and SI at intake and for family/peer relationships the month after intake. Multivariate logistic regression examined associations between relationships and SI, controlling for significant covariates. There were 144 youth (36%) who reported SI at intake; bivariate analyses indicated they had significantly worse family/peer relationships. Multivariate analyses showed that family/peer relationships were associated with current SI, controlling for significant covariates. Results support associations between poor relationships and SI in BP youth, regardless of current mood symptom severity. Clinicians should assess relationships when completing risk assessments with BP youth.