Social bonds, social integration, and primary group relations are central constructs in sociological theory and have been prime considerations within sociological analyses. This chapter begins with a description of prominent conceptualizations of social support. It discusses current knowledge of this topic, paying particular attention to the challenges of assessing both the mechanisms underlying the association between social support and mental health and the causal direction of this association. The chapter considers how the relationship between social support and well-being is importantly influenced by one's social location. The perception of being loved and wanted, valued and esteemed, and able to count on others must be a function of one's history of supportive and unsupportive experiences, with both early life and recent experiences representing major influences. Social support tends to matter for psychological distress and depression independent of stress level. However, it tends to matter more where stress exposure is relatively high.