Research finds that individuals with higher levels of intelligence are likely to save relatively more than others. Evidence from macro-level studies shows that countries with higher than average IQs also are characterized by greater levels of saving. These two outcomes suggest the testable hypothesis: Do countries with higher national average IQs, on average, have more developed financial markets to accommodate this increased savings activity? Using three popular measures of financial development and the Lynn-Vanhanen national IQ measure, I test that hypothesis for a large sample of countries. The evidence indicates that, all else the same, IQ is a significant predictor of financial development.