Purpose - The purpose of this study is to explore and examine the effects of airline deregulation in the United States and South Korea as a comparative analysis. The study focuses on identifying the purposes of airline deregulation and analyzing its benefits and consequences. Research Design, Data, and Methodology - This is a case study, a comparative method, which analyzes and measures the benefits and disadvantages of airline deregulation in both the United States and South Korea. Results - Airline deregulation removed unnecessary and ineffective government controls, resulting in more efficient airline industries in both countries. However, the negative consequences are much greater than the benefits of airline deregulation. Conclusion - The purpose of airline deregulation was to foster an efficient and effective environment in airline industry, and clear evidence of the positive intended effects of airline deregulation e.g., increasing domestic competition, decreasing airfare, increasing productivity, and removing unnecessary government regulations in the beginning of airline deregulation. However, the current state of airline industry in both countries depicts only the consequences of airline deregulation.