Why are so many Koreans named Kim?

Kim is everywhere as a surname in Korea, Koreans named Kim make up millions of the population! It’s almost guaranteed that you have come across this name enough to wonder “Why are so many Koreans named Kim?”.

How Common is the Last Name Kim in Korea?

The percentage of Koreans named Kim in South Korea is around 20%, which ends up being above 10,000,000 people! While 20% is not the majority of people, that is a huge amount. Conversely, Smith (which is the classic American name) has around 2 million people with that last name. There is a saying that references how popular the surname Kim is similar to “like finding a needle in a haystack”

Why is Kim so Common?

The origins of the surname is actually rooted in royalty! Last names used to be more exclusive to royalty and aristocrats but specifically the Kims ruled over Korea for many years. During the Silla dynasty (57 BCE – 935 CE) the Gyeongju Kim clan ruled for over 500 years. And again during the Gaya dynasty (43CE–532CE) the Gimhae clan ruled.

Kim uses the Hanja 金 for gold which ties into its royal connection. The history runs deep for Kim royal leaders in different locations around Korea up until the Joseon dynasty (1300s – 1800s). During the Joseon dynasty after two wars left the country financially depleted; so in an effort to gain more money the monarchy allowed commoners to adopt surnames. Many people choose to adopt Kim because of the royal connection. Later during the Japanese occupation, surnames were made mandatory in a new household registration system and once again many picked Kim.

Thus many people who have the name aren’t related. People are a part of different ‘clans’ (or 본관) which tie them to their ancestorial areas and help to determine who is related. Clans follow along your paternal line so children traditionally adopt their fathers’ last name while the mother keeps hers.

How many Different Kims are there in Korea?

Since different people adopted the surname from different regions there are multiple clans; some with more members than others. I’ll get more into how clans and Korean names work in another post but for now we’re just focusing on the Kims.

There are over 300 Kim lineages still going to this day with the 3 biggest Kim clans being:

1. Gimhae Kim clan (김해 김씨) approx. population of 4,400,000
2. Gyeongju Kim clan (경주 김씨) approx. population of 1,800,000
3. Gwangsan Kim clan (광산 김씨) approx. population of 900,000

Gimhae clan are descendants of King Suro (수로) who started the Gaya dynasty and ruled until 199CE in southeastern Korea. Some popular descendants include members from SHINee, EXO, aespa, Loona, NCT, IKon, and more. Many descendants are also politicians.

The Gyeongju clan is traced back to the Silla dynasty and Kim Al-chi born in 65CE who did not rule himself but his descendants did. I found members from BLACKPINK, Twice, and IKon and actor Kim Joohyuk who are descendants from popular culture.

Gwangsan clan are descendants of a son of King Sinmu of Silla who passed in 839CE. Some popular clan members are members of BTS, Mamamoo, After School, S.E.S., and actor Hyun Bin.

Other major clans come from all over South Korea, with clans from Andong, Uiseong, Ulsan, Jeonju, and more.

Interesting Fact: Korea had Regulations about Clans and Marriage!

I was first introduced to this from the Kdrama Reply 1988, you might remember the concept from it as well! Going along with clans for the longest time Korea had a restriction against marrying someone from the same clan. Now because clans can go back multiple generations and centuries, and with the huge population of Kims for many people it caused trouble. Your partner could be from the same clan but genetically your common relative was from 300 or even a thousand years ago!

Ever since South Korea’s huge growth and development, more and more people moved to cities like Seoul and started to run into this issue. The marriage ban was lifted 3 times (in 1977, 1987, and 1995) with more and more people getting married each time. Some estimates say as many as 200,000 affected couples were married in 1995. Eventually, in 2005 the rule was amended and marriage was only to be restricted between close relatives.