This chapter discusses the long-standing problem of identifying Confucians in China (and East Asia in general) through social science research methods—a problem deeply rooted in the nineteenth-century conceptualization of Confucianism and the overall classification of Chinese religions. It investigates different types of empirical data—national censuses and surveys—from Mainland China, as well as from Taiwan, Japan, and South Korea, in order to answer two questions. First is about whether “Confucianism” is a category in religious classifications in these East Asian countries and regions; the second asks about how many people are counted as “Confucians” in China.