The ageing population has been rapidly growing over recent years. Theoretically, religion seemingly plays an important role in improving older people's health. This study examines whether believing in religion is related to better health conditions among Chinese older adults through a meta-analysis. Two researchers independently extracted the studies from a comprehensive database and grey literature search and evaluated their scientific quality. From the 3,777 potentially eligible papers, just 76 were selected. The pooled effect size detected no significant difference between Chinese religious and non-religious older adults’ overall health and wellbeing. Dividing the outcomes into different categories, religious older adults reported both a higher level of anxiety (Hedge's g = −0.392, 95% confidence interval (CI) = −0.494, −0.290; p = 0.004) and yet a higher level of happiness (Hedge's g = 0.342, 95% CI = 0.074, 0.610; p = 0.018). Having a higher proportion of females in the sample is related to a smaller effect size in overall health outcomes (β = −2.205, 95% CI = −3.800, −0.613; p = 0.007) and social support specifically (β = −4.660, 95% CI = −6.261, −3.058; p < 0.0001). This study is among the first to synthesise the quantitative evidence regarding health differences between older religion believers and non-believers in China. It calls for future studies investigating the pathways underlying the religion–health relationship.