This dissertation comprises three related empirical studies that investigate the relations between CEO overconfidence and various corporate policies. Extant research discovers that when managing their own firms, overconfident CEOs behave differently from non-overconfident CEOs. In addition, overconfidence is a personal trait, which is persistent. This means overconfident CEOs can bring the effect of overconfidence to other firms when they serve as outside directors. Thus, in this dissertation, I not only investigate the impact of CEO overconfidence upon their own firms’ policies, but also the policies of firms that appoint them as outside directors. I begin by examining the relation between CEO overconfidence and debt structure. Then, I investigate the relation between overconfident outside CEO directors and the appointing firms’ dividend policy. Finally, I investigate the relation between these overconfident outside CEO directors and the appointing firm’s acquisition decisions. Chapter 2 extends the studies on debt structure to include CEO overconfidence. Overconfident CEOs overestimate the cash flow generated from a project, and underestimate the risk of a project. As a result, overconfident CEOs tend to overinvest in risky projects. However, debtholders cannot get more benefit from a firm beyond the debt repayments. This means debtholders prefer relatively safe projects that generate stable cash flows. This conflict between overconfident CEOs and debtholders causes some risky projects to be forgone. To pursue all perceived profitable projects, overconfident CEOs want to reduce the monitoring from debtholders. Prior research indicates that less specialized debt structure is associated with less monitoring from debtholders. Thus, overconfident CEOs prefer a less specialized debt structure. I further exploit how overconfident CEOs influence each types of debt to achieve a less specialized debt structure. I test my hypotheses on a sample of 4,238 firm-year observations in the US from 2001 to 2013. I document overconfident CEOs tend to have less specialized debt structure, larger proportion of commercial paper and subordinate debt (low priority) in debt structure. I also document overconfident CEOs have lower proportion of capital lease (high priority) in their debt structure. In Chapter 3, I investigate the relation between overconfident outside CEO directors and corporate dividend policy. Prior research documents that outside CEO directors are related to poorer corporate governance. I provide additional evidence by considering the relation between overconfident outside CEO directors and corporate payout policies. Prior research suggests that dividend payments are a means of mitigating the problem that managers waste money on value-destroying projects. Overconfident outside CEO directors have a tendency to overestimate their abilities when assisting the appointing firms from choosing projects and preventing managers from wasting money. Thus, a board with more overconfident directors is more likely to approve a lower level of dividend payment and allows a firm to retain more funds for future investment. I test this hypothesis on a sample of 11,861 firm-year observations from the US between 1998 and 2010. I find that there is a negative relation between the number of overconfident directors and (1) the probability of paying dividend; (2) the probability of increasing dividend and (3) the amount of dividend. These relations are more profound among outside CEO directors with high levels of overconfidence. In Chapter 4, I examine the impact of overconfident outside CEO directors on corporate acquisition decisions. Overconfident outside CEO directors overestimate their abilities to monitor and advise the acquiring firms during the process of acquisitions, which leads them to hold inflated views of their ability to create value during acquisitions. Hence, I hypothesize that firms with more overconfident outside CEO directors have higher propensity to initiate acquisitions. I test my hypothesis on a sample of 10,738 US firm-year observations between 1998 and 2010. I discover no significant relation between the number of overconfident outside CEO directors and a firm’s decision to engage in an acquisition. However, when the appointing firm has a non-overconfident CEO, there is a significant and positive relation between the number of overconfident outside CEO directors and a firm’s decision to engage in an acquisition. When the appointing firm has an overconfident CEO, there is no significant relation between the number of overconfident outside CEO directors.