Background <p>Previous cross-sectional studies have shown that the main sources of income are associated with health issues, social behaviors, and quality of life. However, the outcomes did not focus on hard endpoints, such as mortality. We aimed to investigate the association between the main sources of income and all-cause mortality in older people using longitudinal data from the Chinese Longitudinal Healthy Longevity Survey.</p> Methods <p>In total, 18,218 older people were included and divided into five groups according to their main sources of income (i.e., family support, social welfare, pensions, work income, and other income). The association between the main sources of income and mortality was estimated by Cox proportional-hazards regression analysis.</p> Results <p>Over a median follow-up of 4.74&#xa0;years, 12,884 deaths were recorded. Compared with the main income from family support, other types of income were associated with a reduced mortality risk, and adjusted hazard ratios were 0.91 (95% CI: 0.84–0.98, <i>p</i> = 0.015) for social welfare, 0.89 (95% CI: 0.84–0.95, <i>p</i> &lt; 0.001) for pensions, 0.63 (95% CI: 0.57–0.69, <i>p</i> &lt; 0.001) for work income, and 0.85 (95% CI: 0.74–0.99, <i>p</i> = 0.031) for other income. Furthermore, stratified and sensitivity analyses showed the robustness of our findings. In addition, among older people relying on family support, exploratory analysis suggested that switching to other types of income favored a reduction in mortality risk.</p> Conclusions <p>Among older people in China, compared with main income from family support, other types of income, especially work income, are associated with a reduced risk of all-cause mortality. Economic independence and stability may be important factors influencing health outcomes. Of course, given the inherent limitations of observational studies, the causal direction of this association still requires cautiousness.</p>