Objectives: This study aims to enhance the understanding of longitudinal associations between two important facets of well-being in late life: social support and commitment to life and living (CTL). Methods: Structured home interviews were conducted with 824 Israelis ≥75 years of age, with three annual data collection timepoints. We hypothesized and tested a cross-lagged, longitudinal structural equation model (SEM) in which CTL and social support were assumed to predict each other over time, covarying for previously reported CTL and social support. Results: Social support has a positive, contemporaneous effect, predicting commitment to living at T1 and T3, while CTL predicts social support the following year (i.e., T1–T2 & T2–T3). Satisfaction with relationships significantly contributes to measurement of both latent constructs at each point of data collection. Discussion: Commitment to life and living and social support are intertwined phenomena. Whereas social support has a concomitant effect on CTL, the effect of CTL on social support emerges over time. This suggests that greater social support fosters greater CTL, leading older adults to nurture social networks and relationships; the effect of which is greater social support in the future. The implications of these results warrant further research over longer periods and across cultures.