The objective of this study is to examine the role of foreign institutional investors (FIIs) in firms' choice of debt. Using a large sample of firms from 40 countries, we find that FIIs are positively associated with the propensity of firms to access the public debt market and the subsequent issuance of new public debt. In contrast, we find no relationship between domestic institutional ownership and public debt. Our results are robust to various specifications, including a 2SLS regression model, a change model, a Heckman two-stage model and propensity score matching model, and a quasi-natural experiment using the exogenous relaxation of foreign equity restrictiveness. Cross-sectional tests further show that findings are stronger for firms with poorer accruals quality, with higher levels of information asymmetry, and firms domiciled in countries with weaker creditor protection. Collectively, our findings suggest that FIIs play a vital role in facilitating firms' public debt financing.