There are over 270 surnames in Korea. The top 5 names on this list make up more than 50% of all Koreans. Kim alone makes up close to 23%. This means that in a population of over 50 million people, for every 5 Koreans you meet, it is highly likely you will meet one Kim. Therefore, having the same Korean last name does not always mean they are related. Throughout Korean history, the last name was determined by the clan or region they were born in. Many of these surnames stem from Chinese characters converted into a different script.