Abstract: Social support is a critical determinant of military service members’ mental and behavioral health outcomes, but few studies have investigated social support types and sources in the mixed family and military social networks in which service members are embedded. We applied multilevel logistic regression modeling to investigate links between active-duty Army Soldiers’ individual demographic and military characteristics, relational characteristics, and social support outcomes, in sample of 241 active-duty U.S. Army personnel. Results showed that participants who rated unit cohesion higher were more likely to report receiving informational, emotional, and mental health help-seeking support. Participants were more likely to receive informational, emotional, and help-seeking support from a romantic partner or deployment buddy than a relative and less likely to receive help-seeking support from males than females. Findings highlight the critical importance of both unit level and external relationships in meeting Soldiers’ social support needs.