Grounded in the international image theory , this study argues that individuals maintain general images of foreign nations that shape perceptions of foreign policy issues. Based on two identical national online surveys conducted in the United States (N = 1250) and China (N = 1311) in early 2019, the study explores the structure and composition of these national images among American and Chinese citizens and tests whether they influence perceptions of the U.S.–China trade war. The findings suggest that cognitive and affective components of national image are associated with the perceived favorability of the other nation and support for the U.S.–China trade war among the American and Chinese public. While media exposure played a more prominent role among U.S. respondents, personal traits such as cosmopolitanism, patriotism, cultural affinity, and personal contact with people from the other nation were significantly associated with people's overall favorability of the other nation and their support of the U.S.–China trade war.