Sleep problems and poorer well-being may be particularly salient for Latino/a college students as they tend to experience sociocultural adjustments during this transitory time. Social connections, a correlate of health, change moment-to-moment for college students and may be experienced differently for people who more strongly endorse horizontal collectivist cultural values. We used ecological momentary assessment (EMA) to examine how in-the-moment social connections influence in-the-moment health, and how horizontal collectivism moderates the moment-to-moment associations. Self-identified Latino/a college students (n = 221) completed a demographic information and cultural values questionnaire and then responded to EMA measures on their social connections, affective and subjective well-being, and sleep for 14 consecutive days. Better in-the-moment social connections associated with better health. Horizontal collectivism moderated some, but not all associations between social connections and health. Social connections are multidimensional and differently predict in-the-moment health among Latino/a college students who more strongly endorse horizontal collectivistic values. We discuss implications for identifying vulnerable well-being moments among this understudied population.