Kim, Lee, Park: Why So Many Koreans Share Common Surnames

Almost half of all South Koreans are named Kim, Lee or Park, because surnames spread from a few prestigious clans as commoners adopted them in the last few centuries.

They are not all related, though. A Korean surname only tells half the story. The other half is the family seat, which we will get to below.

What are the most common Korean surnames?

South Korea’s 2015 census (by Statistics Korea, 통계청) is the most recent count of surnames. Here are the top ten, with the hanja (Chinese characters) each one is written with.

Add up the first three and you get about 44.6%. There is an old Korean joke: throw a stone from Namsan mountain in Seoul, and it will hit a Kim or a Lee.

The census counted over 5,000 surnames in 2015, but that number is a bit misleading. Most are tiny, and many were brought in by naturalized citizens. In the 2000 census, before that wave, Korea had only 286 surnames.

Why do so few surnames cover so many people?

For most of Korean history, surnames were a privilege. Royalty and aristocrats had them; many commoners and enslaved people did not. During the late Joseon dynasty, more and more families bought or adopted surnames, and when the class system was abolished in the Gabo Reform of 1894, the floodgates opened. A 1909 household registration law then required everyone to register a surname.

When you get to choose, you pick a famous one. Kim was the name of Silla kings; Lee (李) was the royal family of Joseon; Park goes back to the legendary founder of Silla, 박혁거세 (Bak Hyeokgeose). So millions of families became Kims, Lees and Parks.

Korean women also keep their own surname after marriage. So if you meet a couple named 김 and 박, they are not hiding anything. By default, children take the father’s surname, though since 2008 parents can agree to give the mother’s surname instead.

Why is 이 spelled “Lee”?

The character 李 (plum) was originally read 리 (ri). South Korean standard Korean has a rule called 두음법칙 (dueum beopchik, the initial sound rule): a ㄹ at the very start of a word drops before ㅣ. So 리 became 이 (i). North Korea did not adopt this rule, which is why North Korean names use 리 and are romanized Ri.

Strict Revised Romanization would write 이 as just I. That looks like the English word “I,” so almost nobody uses it. Instead:

• Lee matches the English “ee” sound and is by far the most common.
• Yi is used by some historians and families (the Joseon royal family is often written Yi).
• Rhee was famously used by Syngman Rhee (이승만), South Korea’s first president.

The same initial sound rule explains 임 (林, originally 림), which is why you see both Lim and Im. It also explains 노 (盧, originally 로), spelled Roh by former president 노무현 (Roh Moo-hyun). For more on why names can ignore official spelling, see why it’s Busan, not Pusan.

"Park" has an r in it that nobody says. 박 is pronounced bak, rhyming with "rock." Early romanizers likely chose "Park" because in British English the r is silent and "park" sounds like pahk.

What is a family seat (본관)?

Every Korean surname comes with a 본관 (bongwan), the place a clan traces its founding ancestor to. Two Kims with different 본관 are, on paper, from completely different families.

The 본관 used to matter a lot. Until the late 1990s, Korean law banned marriage between people with the same surname and the same 본관, even if they shared no ancestor for 30 generations. The Constitutional Court struck the ban down in 1997, and the Civil Act was revised in 2005. Older relatives may still ask a couple, half joking, “Which 본관 are you?”

How should you address a Kim, Lee or Park?

Since so many people share a surname, Koreans rarely use the surname alone. They use a full name, a job title, or a relationship word.

To ask someone’s surname politely, say 성이 어떻게 되세요? (seong-i eotteoke doeseyo?, “What is your family name?”). Note that 어떻게 is said [어떠케] because of ㅎ aspiration, one of the sound changes beginners hear.

Can I get a Korean surname?

If you are just having fun or want a Korean name for class, Kim, Lee or Park will make you blend right in. If you want something a bit rarer, 한 (Han), 서 (Seo) and 송 (Song) are all common enough to sound natural. Try the Korean name generator to pair a surname with a given name, then read what Korean given names mean.

Sources: Statistics Korea (통계청), 2015 Population and Housing Census, surname and clan seat results; National Institute of Korean Language (국립국어원), Romanization of Korean; Constitutional Court of Korea decision on the same-surname marriage ban (1997).

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