Key Factors In The Quality Of Life Of The Elderly: Empirical Evidence From North Sumatra Through Social Network Analysis Introduction The aging population in Indonesia continues to increase, including in North Sumatra which has the potential to enter the phase of an aging population. However, a comprehensive study of multidimensional factors that affect the quality of life of the elderly is still limited. This study aims to identify key factors in the quality of life of the elderly with a multivariate approach and Social Network Analysis (SNA). Methodology The study used a quantitative design with an explanatory approach on 268 elderly people aged 60–64 years in Medan and Deli Serdang. The measurement instrument is a validated WHOQOL-OLD questionnaire. The analysis was carried out with logistical regression of the Backward LR model to determine significant predictors, followed by SNA analysis using UCINET to measure the connectivity and centrality of variables. This study obtained ethical permission and participant consent. Results Nine significant variables (p < 0.05) were found that affected the quality of life of the elderly. The strongest predictors were the ownership of non-government insurance (OR = 19.58), the existence of Posyandu for the Elderly (OR = 13.73), and the activeness of Posyandu cadres (OR = 5.32). On the other hand, the frequency of Posyandu visits showed a negative relationship (OR = 0.035). The results of SNA place the existence of the Elderly Posyandu as the central node with a degree value = 0.750; closeness = 0.800; betweenness = 63.99; then eigenvector = 0.514. Conclusions The results confirm that the Posyandu Lansia is a multifunctional intervention center that connects the health, social and economic aspects of the elderly. Reforming and strengthening Posyandu, expanding health insurance and providing an elderly-friendly environment are important strategies to improve the quality of life. These findings underscore the importance of community-based interventions with local cultural approaches.