Modern Chinese diplomatic histories rarely discuss the marriages of diplomats, leaving the impression that women made little impact on their husbands' careers. The extraordinary performance of Oei Hui-lan (1889–1992), wife of celebrated diplomat Wellington Koo (1888–1985), challenges this view. Hui-lan's contributions to diplomacy call our attention to the role played by Chinese diplomatic wives: as reception hostesses and embassy managers, they cultivated social relationships to facilitate diplomatic exchange. Hui-lan's story reminds us that to study modern diplomatic history solely through the lens of professionalization and institutionalization – while forgoing perspectives of gender and family – is insufficient to explain China's success in this period. Hui-lan's Peranakan family background in the Dutch East Indies (now Indonesia) equipped her with the financial assets and cosmopolitan upbringing to shine as a diplomatic wife. And yet, though she benefited from her overseas origins, Hui-lan had an uneasy relationship to her Chinese identity. Concealing the tension in her two autobiographies, Hui-lan later reconstructed her past, emphasizing her patriotism and ethnic Chineseness to befit her established position. Thus, her case also shows how the complicated process of identity rebuilding and selective adaptation played out for elite overseas Chinese women through their engagement with modern China.