This study identifies the factors of ethical climate in hotel companies in light of the growing importance of ethics in corporate management. It determines the effects those factors have on organizational trust and, in turn, the effect organizational trust has on organizational citizenship behavior (OCB). A survey was conducted on employees working at five-star hotels in Seoul, Korea, followed by an empirical analysis of the data. The ethical climate in hotel companies comprises seven factors: self-interest, efficiency, friendship and team interest, social responsibility, personal morality, rules and standard operating procedures, and laws and professional codes. The following were discovered. First, among these ethical climate factors, social responsibility, personal morality, rules and standard operating procedures, and laws and professional codes affected trust in supervisors. Second, social responsibility and laws and professional codes affected trust in the organization; trust in the supervisor and organization—factors of organizational trust—affected the OCB directed toward individuals and the organization. Based on these results, this study provides ways to increase organizational trust and improve the OCB of employees by creating an ethical climate in hotel companies.