Compared with China's pre-eminent status in world trade, its role in global finance is poorly understood. This paper studies the size, terms and destination of Chinese official international lending on the basis of a new “consensus” database of 4900 loans and grants to 146 countries, 1949–2017. Using the loan-level lending data we estimate outstanding debt stocks owed to China for more than 100 developing and emerging economies since 2000. As of 2017, China had become the world's largest official creditor, surpassing the World Bank and the IMF. The terms of China's state-driven international loans typically resemble commercial rather than official lending. We also find that 50% of China's official lending to developing countries is not reported in the most widely used official debt statistics. These “hidden” debts have important implications for debt sustainability.