This study investigated the effect of loneliness on depression and further tested the mediating effect of social support. A total of 320 elderly persons completed the Emotional and Social Loneliness Scale, Multidimensional Scale of Perceived Social Support, and Self-Rating Depression Scale. Results revealed that loneliness and social support significantly correlated with depression. Structural Equation Modeling indicated that social support partially mediates loneliness and depression. The final model illustrated a significant path from loneliness to depression through social support. This study sheds light on the concurrent effects of loneliness and social support on depression, providing evidence on how to reduce depression among the elderly.