Losses from cyber crime are estimated to cost the global economy US$ 445 billion each year. As financial transactions are carried out increasingly online, the threat from cyber attacks is on the rise. Korean financial institutions have been strengthening their cyber security measures because of increases in cyber attacks; however, with cyber attackers using the most up-to-date techniques, financial institutions still face many challenges. Information systems in the past have commonly used a client server configuration in which the computer networks of organizations have clearly divided the internal and external communication network. This was a situation in which the protection of the connection to the communication network and the user’s end point was the primary concern. The rapid rise of cloud and mobile environments has gone hand in hand with an increase in the types of operating systems (OS), types of devices, and forms of connections in accessing information systems. In particular, security for this mobile environment has been increasing in importance. In addition, there are worries over the increase in state-sponsored cyber attacks, and financial institutions can also affected by such attacks. This article reviews the structure and related regulations of cyber security in Korea’s government, supervisory institutions, and financial institutions. Then these are compared with the current status and legal systems of foreign countries and suggested improvements are provided for Korea’s legal and institutional standing on cyber security in relation to financial institutions.