In diverse societies, individuals tend to trust coethnics more than non-coethnics. I argue that identification with a territorially defined nation, common to all ethnic groups, reduces the degree to which trust is ethnically bounded. I conduct a “lab-in-the-field” experiment at the intersection of national and ethnic boundaries in Malawi, which measures strength of national identification, experimentally manipulates national identity salience, and measures trust behaviorally. I find that shared nationality is a robust predictor of trust, equal in magnitude to the impact of shared ethnicity. Furthermore, national identification moderates the degree to which trust is limited to coethnics: While weak national identifiers trust coethnics more than non-coethnics, strong national identifiers are blind to ethnicity. Experimentally increasing national identity salience also eliminates the coethnic trust advantage among weak nationalists. These results offer micro-level evidence that a strong and salient national identity can diminish ethnic barriers to trust in diverse societies.