In recent years donor countries have committed to dramatic increases in the supply of foreign aid to developing countries. Meeting and sustaining such commitments will require sufficient support among donor country voters and taxpayers. The determinants of public opinion in donor countries on foreign aid have received little attention. This paper examines attitudes to foreign aid with a large, multi-level, cross-national study. It outlines a theoretical rationale for support for foreign aid, discussing the importance of both individual factors and economic and social structures. The theory is tested with multi-level models, including both individual-level and country-level variables to predict positive attitudes. Two datasets are used to measure attitudes in donor countries: (1) the 1995 World Values Survey has information from approximately 6,000 individuals in nine countries and asks a rich battery of questions at the individual-level, and (2) the 2002 Gallup "Voice of the People" survey asks fewer questions of individuals but includes 17 donor countries. Using both surveys combines their distinct strengths and allows tests of individual and national-level theories across disparate samples. The results generally support the predictions that attitudes toward aid are influenced by religiosity, beliefs about the causes of poverty, awareness of international affairs, and trust in people and institutions.