As the second leading cause of death among youth between the ages of 10 and 24 in the United States, suicide is a pressing public health concern. In addition to clinical risk factors such as a history of suicide attempts and psychopathology, several social factors relate to suicide risk, such as high interpersonal conflict (e.g., bully victimization, interpersonal aggression) and low social connectedness. While low social connectedness is associated with an increased likelihood of suicidal ideation and behavior, high connectedness has been shown to have a role in attenuating the effects of bullying victimization on suicide risk. However, less is known regarding the relationships between victimization, connectedness, and suicide risk prospectively or regarding how domains of connectedness may be differentially protective. Additionally, though interpersonal conflict and low social connectedness are empirically supported suicide risk factors, little is known about the role of these factors in the hours just prior to a suicide attempt. Such factors are potentially modifiable and could be important targets for suicide risk prevention efforts. Accordingly, this dissertation is comprised of two studies that examine the proximal and distal relationship between interpersonal conflict, social connectedness, and suicide risk in samples of high-risk youth. The first study prospectively examines the interaction between bullying victimization, social connectedness, and suicide risk in a sample of victimized youth. This study has two primary aims: 1) to examine the prospective relation between bullying victimization severity and suicide risk, and 2) to examine the protective role of connectedness in specific relational domains (family, school, community) in moderating the prospective relation between bullying victimization severity and suicide risk. Participants are youth (N = 142), ages 12-15, recruited from a general emergency department and assessed at three time points across sixteen months. All youth screened positive for bullying victimization. Family, school, and community connectedness were prospectively associated with decreased suicide risk (higher self- esteem, lower depression, decreased suicidal ideation). Moreover, school connectedness was found to protect youth against the negative impact of victimization on self-esteem and suicidal viii ideation. Similarly, school connectedness buffered the negative impact of electronic victimization on suicidal ideation and relational victimization on self-esteem. The second study utilizes a case-crossover design to examine interpersonal conflict, bullying involvement, and social connectedness as proximal suicide risk factors in a sample of youth with a recent suicide attempt. This study has the primary aim of examining whether (per parent and adolescent reports) interpersonal conflict, bullying involvement, and social connectedness are warning signs for suicide attempts. Participants are youth (N = 32), ages 12-17, recruited from psychiatric and pediatric emergency departments who reported a suicide attempt within the previous two weeks. Results indicate that interpersonal conflict and social withdrawal, per adolescent report, are related to increased likelihood of making a suicide attempt. Additionally, interpersonal conflict, bullying involvement, and social withdrawal, per parent report, are related to increased likelihood of making a suicide attempt. Taken together, findings have the potential to inform prevention and intervention approaches focused on targeting interpersonal conflict, bullying victimization, and social connectedness to attenuate suicide risk.