Grounded in the resource-gain-development perspective and research on generational differences, the present study examined the mediating role of work-self facilitation in the relationship between family supportive supervisor behaviors (FSSB) and employee life satisfaction and examined the moderating role of generational differences. We collected time-lagged data with a 6-month interval from a sample of 321 Chinese employees. The results showed that work-self facilitation mediated the relationship between FSSB and life satisfaction. Further, generational differences moderated the indirect effect of FSSB on life satisfaction through work-self facilitation, such that the indirect effect was stronger for millennials than for older employees. The present study contributes to a better understanding of how FSSB might promote employees' life satisfaction and whether this process might affect some employees more than others. The results provide practical implications for fostering employee life satisfaction.